Systems cracker stalks pedophiles.
Brad Willman, known to the underground as Omni-Potent, has stepped forward after three years of secretly stalking online pedophiles and tipping off law enforcement. His primary tool was a trojan horse that appeared to be an image file but was actually a remote access tool that he posted to child porn-related newsgroups on Usenet. People would download and double-click them, which silently installed the utility. He would monitor feeds from multiple installations of this utility for up to 16 hours every day, gathering evidence that he indexed, filed, and passed along to police, even against their orders. Time and again, his data packages were ignored by police in Canada and the United States, but sometimes they'd act on what they'd been anonymously sent, and search warrants and arrests would result.
One of them was even a judge.
Willman is now working on a legitimate information security career.