I guess I go out on a limb here and say I find this whole operation pretty upsetting. Yes, a few predators are being caught and exposed, but that pales compared to other issues, of which the following are just a few that I can think of off the top of my head:
1. Like others have said, this show ignores the fact that more than 90% of abused kids are hurt by people they know. The huge publicity this show gets is enormously damaging not just because it ignores the 90% majority, but even more importantly, because it implicitly suggests that the real peril comes from strangers off the Internet. It gives the idea to parents that if they are vigilant about their PC, then they have their bases covered so far as dealing with the danger of CSA is concerned. In fact, however, nothing could be further from the truth.
2. This program seems to create predators, judging from the fact that most of the guys who are caught are men with no criminal record of any kind. The show goads and baits guys into making the arrangements to meet, pressures them if they falter, and then exposes them and gets them sent to jail. But what is the net gain to society in such a case? Nothing. A predator is not the guy who has unhealthy thoughts, but the one who acts on those thoughts. If the guy's action was provoked by the show, then when they nail the guy all they are doing is harvesting a crop of their own creation.
3. John's comment is a very serious consideration. The purpose of the show isn't to address a problem in society, but to make money, nothing more or less. And Perverted Justice - however much we approve of the results - is just the power trip of one central figure and a few assistants. Do we really think that motives don't count?
4. Perverted Justice encourages scads of volunteers to devote their efforts to vigilanteism and focus on the "stranger danger" when what we really need are people to staff the hotlines, talk to troubled kids, work on awareness programs, advocate for more funding, speak in public, and so on. How many of us know that a LOT of calls to child abuse hotlines fail because of understaffing or poor equipment? The kid is freaking out as he calls, but somehow he does it - and what he gets is a busy signal or a message to hold the line. So he hangs up and never calls again.
5. Justice and the rule of law either prevail or they don't. We can't have the rule of law for most cases, but then, on the side, vigilante mob justice for a few especially heinous crimes. Our codes or criminal and civil justice are build on principles, and when those principles are eroded in some way that is a threat to all of us. Our fathers and grandfathers had to fight a world war over the consequences of that basic fact being ignored, and the menace is still with us today.
6. Thinking about things in terms of absolutes - black or white with no gray areas in between - is never conducive to solving social problems. Simplistic perspectives appeal to our emotions and our sense of moral outrage, but in reality the problems are very complicated and cannot be addressed in this way. A vivid example is Prohibition, which not only failed to eliminate alcohol as a social problem, but also produced a whole generation of new criminals and planted the seeds for what would later become the Mafia.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)