"To Catch a Predator" was an amazing show, still watch compilations on youtube.
Pretty sure they got shut down because one of the guys they busted, committed suicide.
Also, I think it was kind of iffy, the cops working with the vigilante groups, and some cases of entrapment were able to made, since they weren't real cops/didn't follow procedure.
Whole thing's good, but the ender at 6:00 is the best