After 50-year-old UK resident Mary Bale threw a cat in the dumpster for no apparent reason, 4chan was instrumental in tracking Bale down and making sure justice was served. As reported by Gawker:
The subsequent assault on Mary Bale resembled /b/'s harassment of 11-year-old viral video star Jessi Slaughter. They found Bale's employer (The Bank of Coventry), the number of her boss, her address and Facebook profile. As with Jessi Slaughter, they sent death threats and other anonymous mischief her way and Bale was eventually forced into hiding. Except, of course, the moral calculus involved is a bit different here. Can we really feel bad for a woman who would throw away a cat, then say, after she's been busted, "I don't know what the fuss is about. It's just a cat."? Thanks to 4chan, she's being investigated, and has issued an apology.
Internet mob justice isn't always pretty. But it is justice, nonetheless.