Give 'Em Crabs
The URL says it all: crabrevenge.com is an eeeeevil little site in England ("make that bitch itch!") that sells low-level biological warfare for as little as £13.99. Or you could spring for the £34.99 "red package":
Shampoo Resistant F strain Crabs: One colony of F strain super crabs. We have gone through a lot of work but now we are finally able to introduce the F Strain Lice! These crabs are almost impossible to get rid of and have been through over a year of selective lab breeding to be the most aggressive and most reproductive species on the planet! This species can take up to two weeks to get rid of and apparently bite so much they cause the victim to scratch themselves raw and we can guarantee that nothing apart from two washes of everything the victim owns and a 100% delousing solution coverage will get rid of them!
Here's hoping this is just a hoax, designed to swindle petty, vengeful yobs out of their hard-earned pounds.
(Please, please God, don't let anyone starting selling revenge bedbugs. That's a scourge nobody deserves.)