In October of 2016, ProPublica exposed how Facebook's ad-selling system "allows advertisers to exclude black, Hispanic, and other 'ethnic affinities' from seeing ads."

Finding the article "alarming," the office of Washington State Attorney General Bob Ferguson soon launched an investigation. Now, 20 months later, Facebook has entered into an agreement with the State of Washington to halt a practice that Ferguson described as "wrong, illegal, and unfair."

Although the agreement is only legally binding in Washington State, Facebook says it will follow its terms worldwide.

According to Ferguson's office, state investigators following up on the ProPublica story found that Facebook's advertising platform "allowed advertisers to exclude African-American, Latinx and other ethnic affinities from seeing ads" but "did not offer exclusion options for Caucasians."

The AG's investigators also bought 20 fake, discriminatory Facebook ads for restaurants, insurance, apartment rentals, and more.

"Despite discriminatory exclusions and language," the AG's office said, "Facebook’s advertising platform approved all 20 ads."

Over the course of Ferguson's investigation, Facebook announced it was taking some new steps to curb discriminatory ads. But last year, ProPublica reported that those steps had failed significantly.

To demonstrate the failure, ProPublica "bought dozens of rental housing ads on Facebook, but asked that they not be shown to certain categories of users, such as African Americans, mothers of high school kids, people interested in wheelchair ramps, Jews, expats from Argentina and Spanish speakers."

All of those ads, ProPublica reported, were "approved within minutes."

The agreement announced today, according to the AG's office, says that Facebook "will no longer provide advertisers with tools to discriminate based on race, creed, color, national origin, veteran or military status, sexual orientation and disability status."

This and other changes will take effect within 90 days. Facebook will also pay the AG's office $90,000 to cover the costs of the investigation.

Will Castleberry, Facebook's vice president for state and local policy, said in a statement that the company appreciated Ferguson's investigations and was glad to have reached an agreement.

"Discriminatory advertising has no place on our platform," Castleberry said, "and we'll continue to improve our ad products so they're relevant, effective, and safe for everyone.”

Another area in which Ferguson thinks Facebook still needs urgent improvement: political ads.

In June, in response to Stranger reporting, he sued Facebook (and Google), alleging years of failures by the companies to follow Washington State's laws on election ad transparency.

Facebook recently moved that lawsuit to federal court. Google has taken a different route by continuing to face the suit in state court.

According to court filings, both companies recently secured additional time to respond to Ferguson's suit. In one filing, Facebook and the AG's office noted the additional time could be used as "an opportunity to explore an early resolution of this matter."