Go to a website such as Omegle, and type in the interests "pedo", "pedophile", stuff like that, and pose as an underage kid. Go along with talking to the creepy pervs on the site. After a while, get their phone number, or if they're REALLY gullible, their address as well. Then call the police. Get them to track these suckers down. Chances are, these pedos have lots of stuff on their computer that'll get them arrested.

If you know how to trace their IP addresses, that would also come in handy.

Please don't create duplicate posts, we already have this exact idea here:
http://dollars-bbs.org/missions/res/1320553556.html

/sage

I was not aware there was already a post like that. I just joined recently with this idea in mind. My bad.