Most of the names in this story have been changed to preserve the anonymity of truly sick people. That said, to the extent that this story has played out on the internet, it is a matter of public record.

Valerie was lying in her boyfriend's bed early on the morning of September 16, 2010, when she detected what 12 percent of women will face in their lifetime: a tiny lump buried in her left breast.

She didn't panic. She was only 36 and healthy in a typical Northwest way—ate organic, biked 100 miles a week—and her annual breast exam had been blessedly lump-free only four months earlier. And when Valerie called her boyfriend over to cop a feel, he couldn't detect the lump. Neither could the nurse practitioner who examined her later that afternoon. Neither did the mammogram he ordered. It was an ultrasound that finally confirmed what Valerie had felt: a pebble-sized mass that turned out to be stage 2A, HER2+ invasive ductal carcinoma—in layman's terms, a rare, aggressive form of breast cancer that is notoriously difficult to treat.

The mass was so small, her doctor said it was a miracle she'd detected it at all. Then, "when he saw my lymph node, everything changed in the room," Valerie remembers. The cancer had already spread to her left arm. "He said, 'You have breast cancer, it's extremely aggressive, and you have an MRI scheduled for 4 p.m. today. Be there.'"

The following week was a blur of bone scans, blood tests, PET scans, and other tests and terminology that are all but indecipherable for those who aren't profoundly sick or working in medicine. It was a week spent calling relatives, crying long-distance, and adjusting to the abrupt new reality that she might die—soon. And, if she lived, it would be without breasts or the possibility of ever getting pregnant.

"That was probably the hardest to hear—that I could never have children," Valerie says. "I've always wanted to have children."

The bleak news was compounded by the fact that she'd been recently laid off from her job and that, as a relatively new Seattle transplant, most of her family and friends were across the country in South Carolina.

"I didn't have an immediate support system beyond my boyfriend and my cats," she says. "The isolation gets to you—you can't get a hug over the phone. It makes you dwell."

Which is why, two days after her diagnosis, Valerie began to blog about her battle with cancer. She wanted to keep her family abreast of her treatment and, hopefully, find support from someone going through the same physical and emotional struggle she was. She named her Tumblr blog CatsNotCancer because she loves cats (not cancer). Over the course of the next year, Valerie would bluntly document her daily ups and downs: How she named her breasts and the cancerous lymph node she would ultimately have chopped off; her ceremonious Viking boob funeral, where she lit boob-shaped candles and set them adrift in Lake Washington as guests snacked on boob-adorned cupcakes; the shaving of her beautiful red hair for Locks of Love ("I couldn't bear to watch it fall out"); her body's refusal to heal after her first radical mastectomy; how cat purrs help heal a mutinous body; the triumph of revealing her scarred, altered chest on Tumblr for its infamous "Topless Tuesday" shots.

"People see commercials and advertisements with cherubic bald women waving pink ribbons, but that's not talking about breast cancer and the realities of going through active treatment," Valerie explains. "After a few weeks, I discovered that I had a new mission: help people see the grim realities of cancer, so maybe they'd remember to cop a feel at their own breasts or book a checkup."

That mission began with a good-bye letter to her breasts:

"I looked at Mabel this morning (I named my left breast Mabel—my right one is Hazel) and I feel this weird mixture of anger and loss," Valerie wrote less than a month after her diagnosis. "And then I look at Hazel and feel sad too—she's being spared tomorrow but her day is coming very soon. And I wonder how I'm going to feel after the surgery when I see this void where my breasts once were. I have no idea... But I do know this. Tomorrow is the first real step toward defeating this dragon. And I have to view this as war—it is war. And tomorrow is the first battle. So for today, and just today, I'm going to allow myself a little self-pity. I may cry (and when I cry, I cry—think the Ben Stiller scene from Something About Mary. Seriously.) and I may pout. But come tomorrow morning, it's game on. I declare war. And I intend to win."

Valerie's posts were reposted, commented on, circulated around online cancer support groups. CatsNotCancer quickly gained more than 2,100 followers on Tumblr, partly because of her content and partly because Valerie took the time to respond to everyone who left messages on her blog looking for guidance, help, or empathy.

That's how she met Beth three months later, in December 2010.

"She was a fellow blogger who introduced herself and said she was going through treatment for lymphoma," Valerie recalls. "I had just undergone my fourth round of chemo and I was feeling really sick—I had no energy, and my mood was in the dumps. It was an accomplishment to put up a blog post during the day."

Nevertheless, she responded to Beth's overture of friendship, and for the first week, their communication was benign. The 19-year-old Wisconsin native, who appeared physically healthy in photographs, talked about her daily struggles with balancing lymphoma treatments and college classes (she wanted to become a psychologist), and the two talked companionably about their favorite TV show, Lost.

Then one day, Valerie received a note from Beth via Tumblr that simply read, "Can you get pregnant while on chemo?"

It struck a chord.

"I wrote her back and said, 'Well, I can't get pregnant while on chemo...' but I admitted that I didn't know her treatment and couldn't know what she was going through," Valerie says. "I did think that chemo would be really, really bad for a fetus. I mean, it's poison." She urged Beth to contact her oncologist immediately.

Instead, Beth messaged her again, intimating that she'd gotten pregnant after being raped by her uncle.

"I immediately sent her my phone number and personal e-mail address and urged her to call me," Valerie says. Beth called within minutes, and the two had their first phone conversation, during which Beth haltingly explained that her uncle had abused both her and her 6-year-old cousin (his daughter). Over the phone, Beth sounded very young and painfully shy, and yet: "She was almost casual about the whole thing," Valerie recalls. "She was hesitant to even call what happened rape."

E-mails forwarded to me by Valerie confirm her account. "Well, I guess its rape then because I did not want that at all," Beth wrote in an e-mail sent the day after their phone conversation, on December 30, 2010. "That word is so gross sounding to me. It makes me so angry. Like the whole thing is just gross, but secondly, I could have gotten really sick from that! Inconsiderate."

Beth ended the e-mail "Blah, blah, rant over lol :)."

It put Valerie on alert. "I kept thinking 'inconsiderate' is one of the last words I'd use to describe rape," Valerie says. Her skepticism grew when she received a follow-up e-mail from Beth on December 31 that read, "Well...I am officially pregnant. This is my worst nightmare. Horrible. I want to die. I am mortified :("

Mortified?

Despite her suspicions, she continued to e-mail Beth.

"I was trying to keep an open mind," Valerie says. "I'd only known this girl a few weeks, and it sounded like she had people in her life mistreating her. I just wanted to offer what support I could."

And who was she to judge the coping mechanisms of a 19-year-old cancer patient and struggling full-time student who spent Christmas being raped by her uncle?

But while Beth e-mailed daily updates on her mortifying pregnancy—"Aborting it is what [my doctor] would recommend his daughter to do. He doesn't think I could handle it mentally or physically. Blah blah."—Valerie contacted her own oncologist about the content she'd read on Beth's blog. She remembers one about Beth throwing up blood between classes at school, then skipping to the hospital to get a five-unit blood transfusion. "My doc was like, 'There's no way in hell that's happening,'" Valerie says. An adult has 11 to 13 units of blood in their body, total, and from the pictures she'd posted, Beth was a petite woman. If she'd lost half the blood in her body, she'd die, not be home in time to blog about it before dinner.

Nor would the average lymphoma patient have the energy to be a full-time student while undergoing treatment, or risk exposing herself to hundreds of germy students while actively being treated for cancer of the immune system.

But Valerie didn't confront Beth with suspicions that she was faking her sickness. Instead, to preserve her own health and sanity, she abruptly stopped answering Beth's e-mails, texts, and phone calls. "Her lying was so alien as a concept, the idea of outing her horrified me," she says. "Part of me thought, 'There's something horribly wrong with her, and if she is being abused, I don't want to make life harder on her.'"

In response, Valerie says Beth went "totally apeshit."

Munchausen syndrome takes its name from an 18th-century German baron who was famous for embellishing tales of his military exploits to anyone who'd listen. But it wasn't until 1951 that Baron Munchausen became widely associated with another crop of pathological liars: people who go to incredible lengths to fake illness or psychological trauma for the express purpose of attracting medical attention and sympathy from other people. Munchausen sufferers don't just shave their heads and say, "Look! Cancer!" They alter their medical records, starve themselves, install catheters and chemo ports, even convince doctors to perform unnecessary surgeries on them—anything to legitimize the fantasy of their sickness.

"I've encountered two women who've lied to their doctors in order to get mastectomies unnecessarily," says Dr. Marc Feldman, a clinical professor of psychiatry at the University of Alabama, whose latest book on Munchausen is called Playing Sick? "That's how desperate their need for hospitalization and love and attention is."

And still other sufferers have physically or psychologically harmed loved ones to gain attention and sympathy. Munchausen syndrome by proxy (MSP), also known as "fabricated or induced illness," was first identified in 1977. The current Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV for short, describes it as causing or feigning "physical or psychological signs or symptoms in another person who is under the individual's care." Think of a parent putting feces in her toddler's feeding tube (as was discovered via hidden camera in a landmark 2009 case), or caregivers slowly poisoning their wards.

Both forms of Munchausen fall under the umbrella of "factitious disorders," a category in DSM-IV that broadly covers an array of mental disturbances in which people intentionally fake physical or mental illness. The DSM-IV is the definitive guide psychiatrists use to diagnose mental and psychiatric disorders, much like a dictionary of mental illness. If a disorder isn't identified in the DSM-IV, psychiatrists won't diagnose for it—either because they don't know about it or because insurance companies won't pay for it. So it's as if the disorder simply doesn't exist.

Munchausen and its proxy are both considered impossible to prevent and difficult to diagnose. Sufferers spend years of their lives cultivating symptoms and memorizing medical knowledge with the crazed focus of a model train hobbyist. They must; their goal is to fool medical professionals into treating them, while cultivating as much attention and sympathy as possible. If they fail, these people simply bounce to the next hospital, or illness, or audience.

A 2011 case report on factitious disorders published in Innovations in Clinical Neuroscience suggests that roughly 9 percent of inpatients in tertiary care (specialized treatments, like cancer care) suffer from some form of factitious disorder. There are no reliable statistics on how many people suffer specifically from Munchausen syndrome—partly because it's hard to obtain accurate data from people who lie pathologically—but the condition is considered rare.

Munchausen syndrome by proxy is also relatively uncommon. A British pediatric research group estimates that only one child in every 5,000 is a victim of MSP, although other studies have put the number as high as one child in every 1,100.

However, in 2001, Dr. Feldman identified a new manifestation of the syndrome, one that isn't listed in the DSM-IV but that he claims is far more common than its cousins: Munchausen syndrome by internet.

Valerie's silent treatment didn't deter Beth from contacting her repeatedly, even obsessively, in early 2011. And when her calls, e-mails, and texts went unreturned, her 6-year-old abused niece evidently e-mailed Valerie to say that Beth had been hospitalized. "I'm not supposed to be on Beth's computer or her e-mail but I'm really scared :((((((((((((((((((((," the supposed girl-child wrote on January 1. "She has to go to the hospital now and now she has ambulance and if she dies and all this blood coming from her mouth again and why does this always happen and the. If shes there fir ever than she won't be home when I'm all alone and I will cry :((((( I'm so scared for her and for me :(((."

Despite her supposed hospitalization, Valerie noticed Beth was still blogging like a champ, so she didn't respond. Another day, another message, this time from Beth herself: "Did I do something to offend you? If I did, I'm sorry."

"When I didn't respond to even that, she wrote an e-mail to apologize, and I thought she'd leave me alone," Valerie says. "I honestly thought that was the end of it."

Valerie turned her mind back to more important things, like winning her war on cancer. She was a quarter of the way through 16 rounds of chemo treatments, with one breast and 10 lymph nodes down and one mastectomy to go. Each day presented its own challenge. Most nights she couldn't sleep. There was constant pain in her chest wall and along her arm, where her lymph nodes used to be. Her skin was paler than potato flesh. Clothes felt unbearably abrasive. Her left arm wouldn't stop swelling. She was tired all the time but couldn't sleep. She was wasting away but couldn't eat. She missed riding her bike. She mourned her health.

It's important to note that Valerie not only shared these struggles on her blog but with a tight-knit group of women she met online. While she was still chest-deep in the war, she'd won an important battle: She'd found a virtual cancer support group of 10 women, all of whom were undergoing treatment for a potentially fatal illness.

Valerie had met each of the women through blogging. The women all lived across the country but they kept in touch through their blogs, texts, phone calls, and e-mails. They shared each other's treatment schedules, wig purchases, and daily consolations and desolations by embracing a level of minutiae that lends itself better to real-life friendship than blogs.

With these women, Valerie could talk about how round after round of chemo had turned her body from a svelte 127-pound cycling machine to a frail 114-pound sack of organs that got winded on a treadmill, but despite it all, how goddamn happy she felt to still be walking. She could talk about how futile it was to interview with prospective employers (she'd been unemployed for more than a year at this point) when she looked like lipstick on a corpse.

She could also talk about her anonymous troll. The one who'd appeared as her blog gained popularity, taunting her with childish nicknames like "Voldemort" and sending untraceable messages like "Everyone wants to watch you die."

What could be done about it? "Practically nothing," Valerie admits. "It was a harsh reminder that on the internet, you can say anything you want, and you can pretend to be anyone you want." So she filtered her Tumblr messages and, with encouragement from her friends, tried to put the troll out of her mind.

Then in May 2011, tragedy struck Valerie's support group: Kate, a 19-year-old leukemia patient who'd recently undergone a bone marrow transplant, fell into a coma.

"The rest of us rallied around her," Valerie says. "We called her friends and family. It was dire."

While they posted to her Facebook page, prayed, and round-robinned the loved ones at Kate's hospital bedside, tragedy struck again: A second woman in the group fell comatose.

Coincidentally, Jen was also a leukemia patient from the Midwest and was almost the exact same age as Kate. When not comatose, Jen—a talkative girl with decisive eyebrows and a moony grin—described herself as a two-time cancer survivor, according to close friends. She was cured of leukemia as a child before being diagnosed with stage 4 neuroblastoma (a form of infant nerve cancer). At that point, according to Jen, an army of doctors declared her a lost cause until, miraculously, one rogue surgeon armed with a new experimental treatment sent her cancer into remission.

Jen was an orphan. In lieu of family, she said she was living with her former medical first responder course instructor, Chris Swanson, and his kind wife. As Jen explained it, Chris had taken a shine to her while teaching a course at her college and had brought her home for keeps. Like a puppy.

Valerie and the group were used to hearing from Chris. Whenever Jen was hospitalized—and this coma wasn't her first—Chris blogged and texted from Jen's accounts on her behalf. Valerie thought it was a little weird that a grown man (a medical first responder, no less) didn't appear to carry his own cell phone. Still, she didn't think to question him about it. Who would?

So while the two young leukemia patients languished in twin Midwestern comas, Valerie and her friends split their precious time and tenuous energy between their own treatment schedules and checking up on the health status of their hospitalized friends.

Then, in June, after posting another encouraging message to Kate's Facebook page, Valerie noticed a chilling detail about Jen's account: There were absolutely no "get well" messages posted anywhere.

On a sickening hunch, Valerie called every hospital in and around Jen's hometown of Ann Arbor to see if they had a patient registered under her name. None did.

"I was so mad, I couldn't breathe," Valerie recalls. "I saw stars—rage stars. How could this be happening again?"

Since Munchausen syndrome by internet isn't in the DSM-IV, the best way to detect it is to know the signs, says Dr. Feldman.

Like other forms of the disorder, Feldman explains that Munchausen by internet usually manifests in the late teens or early 20s. It's often preempted or accompanied by other psychological issues, most commonly personality disorders. And it predominantly affects women. "I'm not clear on all the reasons for that, but it's a pretty consistent finding," Feldman explains. "And many of them have medical or nursing training... Their fascination with medical issues is expressed in their career choices."

The lies escalate slowly, which makes them harder to detect. Someone might sound like a walking textbook when talking about their symptoms, or they may be quick to duplicate the symptoms of other people around them. The lies are intricate, detailed, engrossing. Terrible setbacks are followed by miraculous recoveries. And if someone else becomes the center of attention, their condition will dramatically worsen or they will become the victim of a sudden tragic event.

"A death in the family is common," Feldman adds. "They're usually gruesome deaths or multiple deaths—like a motor accident that kills the entire family. Either that or they're surprisingly vivid, like someone describing a decapitation in vivid detail."

Some people even invent tertiary characters—friends, siblings, a concerned mother—to jump into internet threads and corroborate their stories.

The lies slowly escalate, pile up, and create an improbable whole. Then one day, you realize you're friends with a 15-year-old chronic migraine sufferer online who also happens to be a fourth-year medical school student who plays drums in a band at night—despite those crippling migraines—to pay his med school tuition because his deaf mother and alcoholic stepfather have no interest in his baby-genius education. Oh, and since he's not yet old enough to drive, he skateboards three miles a day to get to class.

And on that day, you feel like a total schmuck.

This schmucky feeling is a byproduct of the internet. Our natural bullshit detectors are muted online; we can't rely on facial expressions and other physical cues for sensing lies, and studies suggest that without those cues, we're prone to generously fill in the blanks.

"People fill in the missing pieces in the picture of others they meet online, not fully aware that the picture they are forming is based partly on their own unconscious desires regarding who they want that person to be and how they want them to act," explains an August 2012 study of the disease titled "Munchausen by Internet: Current Research and Future Directions," conducted by Bournemouth University's School of Health and Social Care in the United Kingdom. "This occurs at the same time as the person is taking advantage of the anonymity inherent in text-only communications to present their best possible face."

Even lacking any medical experience, the internet makes it simple enough for people to become experts on any illness or injury—if not enough to fool a doctor, at least savvy enough to fool other people online. A survey by the Pew Research Center published in 2011 found that 8 in 10 people use the internet to access health information, making it the third most popular online activity (after checking e-mail and using search engines). The Pew survey also found that 65 percent of adults who used the internet for health research reported suffering from a medical crisis in the past six months, which helps explain the internet's robust niche of medical support groups.

"What we're seeing is people spending just 15 minutes researching an illness on Wikipedia and then jumping from support group to support group online," Feldman says.

Think of it: You're anonymous—you can manifest any symptoms you want, like puking pints of blood, without having to actually puke pints of blood. And instead of being examined by the trained eyes of a doctor, you're welcomed unconditionally by flocks of people who stand on-call, ready to shower you with attention and emotional support 24 hours a day. For weeks or months or years, you can live out your deception without the fear of having your lies challenged in person. And if someone does eventually doubt your story, you can simply log out. Change your name or your illness. Find a fresh group of sympathizers.

This accessibility makes Munchausen by internet "way, way more common than Munchausen ever was or could have been," Dr. Feldman says. "Unfortunately, a lot of therapists have no clue what Munchausen is, let alone Munchausen by internet."

Which is dangerous, not only for the sufferers who feed their very real psychological illnesses online, but for the people they prey on. People who seek virtual companionship because their immune systems are truly shot, their days are truly numbered, and they're desperate to pour their trust, love, and dwindling energy into the few people out there—people they can't otherwise reach—who know exactly what they're going through. It's these people, who are already battling the betrayal of their bodies, whose worlds have essentially been reduced to bedrooms and hospital rooms, that Munchausen by internet hurts the most.

Valerie felt stupid for being duped by Jen, another young woman faking cancer. But more importantly, she was pissed—imbued with a rage not even chemo could mute, a rage that burned brighter than 10,000 floating boob candles. But before confronting Jen, Valerie took an important step: She tracked down Chris Swanson and called him.

It turns out that at least part of Jen's story was real—Chris Swanson does exist. In fact, he's Captain Chris Swanson of the Genesee County Sheriff's Office, a handsome 39-year-old with a heroic jaw line and friendly Midwestern drawl. (It might seem weird that, of all the players in this complicated story, Captain Swanson is the only person to not request a pseudonym. He assures me that he is proud of his work and happy to speak on the record.)

"I would characterize her as outgoing," Captain Swanson says when I call him. He remembers Jen from his medical first responder course. "She always sat in the front of the class, middle row." He says she'd often stay after class to talk about her rough life—how she lived alone, how both her parents were dead, how she was fighting cancer. "With her, there was always a new dramatic, horrific story." He could tell that most of her stories were "probably not legit. I'm a cop."

While he was polite to her, Captain Swanson tells me that he never invited her to come live with his family. In truth, he hasn't seen her since her class ended. After Valerie alerted Captain Swanson that Jen was claiming to live with him, he immediately alerted the university about Jen's claims. "I wanted to document that I made the school aware of what was going on," he says. "She wasn't at all threatening, but you never know what people can do online, the venom they can spew. I've been teaching since 1997; I'm cautious around my students."

Within moments of getting off the phone with Captain Swanson, Valerie sent the allegedly comatose Jen a text: "I just got off the phone with Chris Swanson. You and I need to talk about the future of your blog. Call me now."

Instead, Jen immediately defriended her and the other women in her support group on Facebook. She then blocked them from her Tumblr blog. The changes came within seconds of her text, Valerie recalls, "before I'd told anyone else what I'd learned."

Robbed of the emotional gratification of confronting a woman who'd spent half a year scamming sympathy from cancer patients, Valerie was then forced to out Jen to their support group. "I can't express to you how horrible it was to have to confess someone else's lies," she says.

In fact, it caused her to quit the internet.

Valerie figured she still had one boob to lose and a war to win. She couldn't waste any more time on virtual predators and their pretend illnesses.

And so without fanfare, Valerie shut down her Tumblr blog in June 2011.

Within weeks, internet friends were contacting her, some with concern, others with suspicion. They wanted to know how her treatment was going; they wanted proof that her treatment was real. "In my absence, Jen went on a tirade trying to convince people on Tumblr that I was faking cancer," Valerie says. Her solitary troll multiplied into an army. Some accused her of faking cancer, while others gleefully wished she'd die from it, soon.

About a month after shutting her blog down, she relaunched CatsNotCancer.

"I brought my blog back with the sole purpose of setting the record straight," Valerie says. "I went ahead and outed the holy shit out of Jen to the whole world."

Or at very least, the whole internet.

"Munchausen by Internet," the Bournemouth University study published in the Journal of Medical Internet Research, hypothesizes that many Munchausen by internet sufferers are motivated by one of two dominant personality traits: narcissism or sadism. Narcissists don't form online relationships to build interpersonal intimacy; they do it for the audience or to appear popular and successful. When confronted about their deceptions, narcissists are prone to cut their losses and shut down their blog or leave their support group, only to replant elsewhere under a new handle. Sadists, however, "actively seek to disrupt and cause problems for their own satisfaction or enjoyment," the study says. When confronted about their deceptions, these people fight back, and they fight dirty. For this reason, the study notes, they're often lumped into the same category as internet trolls.

To some extent, the label fits. Even Luddites know that internet trolls are those anonymous assholes who deface blogs, news articles, YouTube videos, even tribute pages to dead children by ceremoniously calling someone fat or a fag or whatever. Anything to prompt readers to froth at the mouth. Trolls are a normal byproduct of online socialization—as ubiquitous as cat videos and cash-poor Nigerian princes. The only way to deal with them is to ignore them. Do not feed the troll (DNFTT), as the saying goes.

But there's an important difference between standard internet trolls and a Munchausen by internet troll: the setting in which they operate.

Because unlike standard trolls, Munchausen by internet trolls infiltrate the "open trusting environments of communication forums—established for the sole purpose of giving support to members facing significant health or psychological problems," the study says. It's easy, given the trusting, intimate nature of support groups. They prey on those who are physically sick and, by proxy, emotionally vulnerable. By the time they're discovered, they know their victims quite well. And when their duplicity is unmasked and that attentive support stops, they attack.

"You think that everyone cares about your journey and your bald little head. no one cares. they just want to watch you die."

Valerie's Flickr page, where she photo-documented her cancer journey, and which is now littered with vitriolic comments like the one above, eventually satisfied most of her online critics that she was being treated for cancer IRL (in real life). In them, Valerie resembled a fresh-plucked chicken, minus the breast. But for those who might still have doubts: I've met Valerie. Her hair is a short, red, curly mop, and the pallor of her skin advertises her recent fight with cancer more loudly than her flat chest.

Valerie was disgusted that she had to submit proof to strangers of her suffering, but as she prepped for her second mastectomy that summer, she blogged to stay vigilant. Jen was still active on cancer sites and had popped up in other support circles. Every time she did so, Valerie made it her mission to inform the group of her lies.

Valerie discovered Munchausen by internet after harnessing the power of internet search engines to research "crazy bitches who fake cancer." So she blogged about that, too.

Which is how she met Alex in July 2011. The 19-year-old Texan reblogged Valerie's post about Munchausen by internet, then followed it up with a friendly e-mail. "I just stumbled upon your blog and just want to say, you're incredible," she wrote. Valerie didn't respond. She figured she'd had enough internet friendships.

But Alex was persistent. She uploaded a YouTube video to her blog titled "Dear Valerie." The video depicts a bald girl with a cap pulled down to her doughy cheeks. She looks like any other young white teenager, minus eyebrows. Alex doesn't say much in the five-minute video. The girl stutters as she talks. She's racked by seizures. She flatters Valerie a little, then asks after her boyfriend and mentions Valerie's remaining breast by its Christian name: "I'm thinking of you a lot, lately—you and Hazel and your cats."

Still, Valerie was hesitant to accept Alex's overtures of friendship because her narrative was suspicious: Alex presented herself as a young, partially deaf woman suffering from terminal cancer, which was a byproduct of her status as an AIDS patient. On her blog, she explained that she was infected with HIV as a child after being raped by her uncle. She lived with her vaguely sadistic mother—a woman who allegedly discussed gassing her daughter's pet cat the moment Alex died. But unlike the fakers Valerie had encountered online, Alex had photographs of herself hooked up to catheters, chemo ports, and oxygen machines to back up her claims. She also had friends—"real" friends, not internet ones—who vouched for her terminal status, including one named Gabby.

"I visited her in Texas twice in about a year," Gabby recalls. Gabby's a 24-year-old Midwesterner who suffers from fibromyalgia. She met both Alex and Valerie online. "I pushed around her wheelchair and carried around her oxygen tank, which was heavy as heck."

And here this young, dying girl was, pleading for Valerie's friendship.

"My partner and I are never going to have children. I love children, and here's a girl making the full-court press of friendship with me," Valerie remembers. "I couldn't ignore what I thought were the pleas of a dying child."

Within weeks, the two were talking, e-mailing, Skyping, and texting on a daily basis. Valerie Skyped with Alex from her hospital bed on August 30, 2011, within hours of undergoing her second mastectomy. Valerie promised the girl that if Alex died, she'd adopt Buddy the cat, so Alex's mother couldn't euthanize him. She sent the girl more than a hundred dollars' worth of gifts that she bought off of Alex's Amazon.com wish list. Valerie's boyfriend also routinely Skyped with Alex, as did Valerie's mother. In fact, Alex called Valerie's mom "grandma."

While Valerie's relationship with Alex bloomed, so did her health. Her second mastectomy healed beautifully, and her hair was coming in, giving her a flaming pageboy look. Her cheeks gradually shed their corpselike pallor; muscle tissue strengthened her atrophied limbs; she could hold down food again. And she spent less time online, which translated to less attention on Alex as Valerie worked to reclaim her "normal" life. But while Valerie's health had improved, Alex's health and moods had plummeted. She'd recently confessed to being suicidal.

For the first time in a year, Valerie could venture out into public and be seen as someone other than a cancer patient caught mid-waltz with Death. What better way to celebrate that important milestone than by dressing up as the walking dead and attending a zombie-themed convention in Seattle? That's just what Valerie did. She even invited her fellow nerd-in-arms, Gabby, the friend of Alex's who had vouched for Alex's illness, to fly into town and join her. The pair agreed not to tell Alex about the convention or even Gabby's visit, to spare Alex's feelings.

On October 22, 2011, Valerie and Gabby arrived at the Seattle Center dressed as Beetlejuice and Lydia. This is what happened next:

"I got a phone call from someone claiming to be Alex's mother," Valerie remembers. "She told me Alex was comatose in a hospital but had awoken long enough to call my name." The call threw Valerie off. Although the call's phone number was unfamiliar, she could've sworn on a stack of Bibles that she was talking to Alex, just based on the sound of the voice on the phone. So Valerie turned and asked Gabby if Alex's mother sounded like Alex. Gabby, who'd met the woman several times, said "No."

"And I said, 'Gabby, I think we have a problem here.'"

The women immediately called Alex's IRL best friend in Texas. This best friend revealed that she'd recently accused Alex of faking cancer, faking AIDS, even faking seizures and hearing loss to thousands of people online and in her personal life. (According to a later police report, Alex's victims included the Olympia-area musician Kimya Dawson, who "spent $562.95 at Amazon to send numerous gifts, etc. to her.")

Valerie then called Alex's local police department and asked them to do a welfare check on the girl. Their response was devastating. When questioned by police, "[Alex] stated that she had lied to all her friends and everyone she knows and convinced them that she was dying," the police report states. "Mother stated that her daughter has a disorder and they are working on it."

Even a year later, Gabby can't hold back her tears when speaking about Alex's deception. "Last year, I found out my grandfather had an inoperable tumor in his stomach," Gabby says. "I wrote about it on my blog." Shortly after that post, Alex wrote on her blog that the reason she'd been throwing up continually was because she had an inoperable tumor in her stomach. "Then she asked me to come visit her," Gabby remembers. "My brother, my mom, my uncle, they all went to see my grandfather in hospice. I was faced with the choice of going to see my friend—who for all I knew was dying alone—or going to see my grandfather, who I knew was surrounded by family. So I chose to drive all the way to Texas. I went to take care of her. I did what I thought was right."

Gabby's grandfather passed away weeks later. "I never got the chance to say good-bye to my grandfather," Gabby says. "She knew my grandfather was dying, and she begged me to see her instead."

"New cases of Munchausen by Internet are identified regularly," write the authors of "Munchausen by Internet," but diagnosing it can be tricky given that there's no known way to prevent Munchausen from manifesting in any of its forms, and Munchausen by internet isn't even recognized in the DSM-IV.

That hasn't stopped people like Valerie from launching online crusades to out these pathological fakers. One blog, called the Warrior Eli Hoax Group, was launched last Mother's Day to untangle a complicated nest of lies involving a fictional child with cancer named Eli and his entirely fictional family. Since then, blogger Taryn Harper Wright has investigated a number of online hoaxes forwarded to her by suspicious readers and victims. Wright's blog now gets roughly 2,500 hits a day.

Meanwhile, this body of researchers is lobbying to make Munchausen by internet a recognized psychiatric disorder, which will help psychologists identify and treat patients. The authors of "Munchausen by Internet" "propose that Munchausen by Internet and Munchausen by Internet trolling should be formally acknowledged in a revised version of the Diagnostic and Statistical Manual DSM-5." They argue that updating the DSM, the fifth edition of which is due out in May 2013, would help benefit victims like Valerie by "effectively identifying and minimizing the growth of this behavior as more people seek reassurance and support about their health in an online environment."

Like the other forms of Munchausen syndrome, Dr. Feldman says there are no magical pills to treat the disorder—just intense, dedicated sessions of psychotherapy.

Alex is surprisingly candid about her deceptions when I call to get her side of the story. She's upbeat, even laughing at herself as she tells me about her overpowering compulsion to be liked, to be the center of attention, to lie.

"I'm just full of bullshit and I have been since I was 4," she says, recalling her first lie: "I told my mom I had kiwi at preschool for a snack. Had I ever eaten kiwi in my entire life? No. But I told her in great detail all about the kiwi, how it was hairy on the outside and green on the inside. I don't know where I got these details."

As I'd been warned, she is incredibly charming and her bluntness is ingratiating. At one point, she interrupts our conversation to point out how the cadence of her voice has subtly changed to match my own—she's a Texas girl with a disappearing drawl. It feels as if she's trying to prove something, as if copping to the chameleon-like habit proves that she's now an honest woman. I like her. She strikes me as a woman who could sell autographed Bibles to a used-car dealer.

Alex essentially admits that lying has ruined everything good in her life. Her lies have alienated her from her church—she once swore her mother was pregnant with a Christmas miracle baby, despite having her tubes tied. They've cost her friends and gotten her kicked out of her college dorm, which is how she came to be living back at home at the age of 19.

But Alex swears that she didn't start blogging in November 2010 with the intention of lying about cancer, AIDS, and rape, or manipulating her friends into changing her adult diapers (yes, that happened). The deception began with an opaque post here and there. "Oh I'm sick again" posts, as Alex calls them. "No one paid attention until I started full-time illness blogging." So in April 2011, she ordered two wheelchairs, oxygen tanks, face masks, some veterinary IV tubing, and other medical equipment from Amazon.com. She also cut her hair off and told her IRL best friend that she had non-Hodgkin's lymphoma. She reasoned that this would help validate her story.

I ask Alex why her mom went along with the ruse, why she agreed to pose in pictures that featured Alex wearing an oxygen mask or languishing in a makeshift hospital bed. "I think after living with a child with mental illness for a really long time, you learn to just not push it," Alex responds. "Whenever she would push it with me or I would get caught in a lie, I became acutely suicidal."

Alex says that the blog eventually became her inspiration—and vehicle—for a melodramatic, drawn-out suicide plot. She planned to kill herself in December 2011. "People were not going to know that I had killed myself, though—they were going to think I had died of natural causes," she explains. Death by fictitious cancer.

I'm not sure I believe her, but it hardly matters: Alex's lies were exposed in late October 2011. I ask if she feels remorse for deceiving basically everyone she's ever met.

"Yes," Alex says immediately. She currently limits her internet use and sees a psychotherapist to help her cope with a slew of mental disorders. But Alex admits that even her remorse comes from a very self-involved place. "I'm always the most afraid that people are going to hate me," she says. "People hating me is something that I just can't physically tolerate. It's why whenever I get caught in a lie, I immediately become suicidal and just feel the need to die. Like I can't live with it."

That's what Alex says happened last fall, after her friends outed her lies to her 1,500 internet followers and real-life friends, and the hate mail began. "I took the yellow-belly approach. I sent out a text that said, 'I know what I did was terrible.' People didn't respond to it well. I was publicly mocked." Then she spun into a self-destructive cycle of what she describes as "passively suicidal" binge-drinking.

But instead of dying, the 19-year-old wound up pregnant.

That November, Valerie filed charges against Alex for wire fraud, as much out of spite as the vain hope of recouping money for the stuffed animals, clothes, and other Amazon.com gifts she'd sent the "dying" teen. She also continued blogging about her cancer recovery as a way of putting the whole ordeal behind her. It worked, for the most part. She didn't hear the name "Alex" again for nearly a year. Then, on August 10 of this year, an anonymous note landed in her inbox:

Subject: Alex

Message: Hi Valerie, I don't know if you've heard, but Alex had a baby.... I'm very concerned... about the child. I don't know why because she hasn't shown that she would ever hurt a child, but she seems a little unstable... and that is a little scary. I don't know what needs to be done, but I'm sure you have a better idea of how fit she is to be a mother than I do.

Attached to the e-mail were photographs of a beaming Alex cuddling a newborn. Valerie immediately had visions of Alex ramming a tube up the baby's nose for attention. In fact, she even suspected that Alex had sent the pics herself, if only to taunt her with images of something she could never have: a baby.

"It was a kick in the gut," says Valerie. "Whoever sent it pretty much knew how to hurt me."

In response, Valerie called Child Protective Services and reported the new mother, as did other internet bloggers once she spread the word that Alex had given birth.

Then, when she checked the sender's e-mail address against her Tumblr and Flickr accounts, Valerie realized the e-mail was sent from a familiar source: It was the same anonymous troll who'd taunted her for years—the one who called her "Voldemort" and talked about wanting to watch her die.

Which meant the sender couldn't be Alex because the troll predated her by half a year.

Valerie contacted Taryn Harper Wright from the Warrior Eli blog to help her track down and unmask the troll, once and for all. When Wright began writing about the saga, the troll popped up in the comments section. Using the sender's IP address, the pair were able to track years' worth of harassing messages back to a surprising source: Beth, the teenager who first claimed she'd been subjected to Christmas rape by her uncle and who went "totally apeshit" when Valerie stopped communicating with her.

"I was floored," Valerie says. "Our relationship only lasted a few weeks. I hadn't spoken with her in years. Why would she keep following me? Why would she want to hurt me like that?"

I call Beth to ask her. Unlike Alex's cheery (albeit fair-weather) Southern drawl, Beth's voice is soft and high-pitched. It sounds like it belongs to a girl much younger than her 21 years. During our phone conversation, she admits that she sent Valerie the e-mail about Alex's baby but insists that it was because she was "concerned," not vindictive. You see, Beth had tracked Valerie for years online and, once Valerie outed Alex as a fraud, Beth befriended Alex on Facebook.

She says she contacted Valerie after seeing a picture on Alex's account of Alex holding a baby with a feeding tube. "I thought, 'Oh my gosh.' It freaked me out." (Alex admits that she posed with a picture of a lifelike doll with a feeding tube months prior. "I think it was just another way to get attention and be noticed," she says.)

I ask Beth why she faked lymphoma. She says she did it out of boredom and only once, with Valerie. I ask her about the rape, and she says she doesn't want to talk about it. I ask Beth about sending harassing messages to Valerie over the years—messages about wanting to watch her die, messages that were all sent from the same e-mail address that I used to contact her. Beth freezes up and claims to not remember sending the notes. It seems obvious to me that she's lying. It's written right there, in her voice: "I don't think... I might... I think I might have, once, in the very beginning, sent her a mean note. Yeah, I guess."

I ask her if she regrets her lies. "I realize it was the totally wrong thing to do in that context," she replies. "I do feel bad, and I'm trying to do better things with my time—productive, healthy, good things."

I ask her if she's in therapy. "Yes."

Is it working? "I don't know," she says. "I mean, I guess."

In another part of the country—a distance that is rendered moot online—Alex has started blogging again, this time about motherhood. Her watchdog critics are enraged. They question her right to blog, her very right to exist on the internet after so many lies. (Although, if lying were illegal, the internet would have a population of 10.)

Alex addressed her critics in a November 1 blog post:

Yes, I'm blogging and making friends again. But I'm not lying this time... I'm not making dramatic posts, not spinning webs, just reblogging quotes, interacting with people my age, and being a college student as well as a mother. I'm able to interact with people in a normal way for once in my life and it's refreshing....

I know that I am not the victim in the drama I caused, that mental illness does not excuse what I did, and that I was indeed the bad guy. I've actually started to forgive myself, and have to work to not do it again.

But Valerie finds it difficult to believe Alex, and even harder to forgive her.

"I hate her," she says. "There's a part of me that hates me for hating her, but there are absolutely no repercussions for Alex and the other people out here doing this, and the devastation she caused... There's simply no excuse for repeatedly, deliberately causing harm to other people. And I absolutely think she's capable of doing it again."

Valerie's red hair is coming back as slowly and surely as her health, but she must remind herself to eat because, as a side effect of chemo, her brain no longer tells her when she's hungry. Her teeth have also been weakened by chemo, and doctors say it's even subtly changed the shape of her eyes. Valerie hasn't been cleared to ride her bike again—that will take months of physical therapy, she says—but she jokes about battling less drag when riding, thanks to her double mastectomy.

And even though she's still undergoing targeted chemo treatment and will routinely see an oncologist for the rest of her life, she's shut down her blog for good. "You assume when you start treatment, that it'll be over," she says. "But when you've had cancer, it's never over. It follows you for the rest of your life. I can't control that, but I can at least control the impact these women have on my life—and that's what I intend to do. I intend to lead a happy, full, healthy life."

Her CatsNotCancer page now simply reads "Please... GO AWAY." recommended

This article has been updated since its original publication.