What bothers me about this group is that their primary motivation seems to be attacking pedophiles, rather than protecting children. I realize this sounds like semantics, however there is a real difference. Read through their site and its attached material. The majority of these people seem to need some 'outlet' for what strikes me as a massive reservoir of hostility, and pedophiles make a convenient target of such hostility. Given the current mania with regard to sex offenses (I am not minimizing sex offenses, I am just pointing out that American society has worked itself into a swarthy froth over sex offenses lately), nobody is going to strongly oppose what these people are doing.
If these individuals were truly out to help children as their primary motive, they would stop at alerting police once a positive identification had been made. The process of rabidly sullying the alleged pedophiles goes above and beyond the necessary effort required to simply remove pedophiles from circulation. They seem to revel in the punitive portion of their activities. Read the links from their homepage intended for people who have been recently named, or the associates of those people. Those pages carry a palpable arrogance; 'we just screwed you, there is nothing you can do. We have all the power, you have none.'
The problem here is that pedophiles just happen to be the current target of opportunity. How much difference in mentality is there between these people and homophobes who murder homosexuals because they are disgusted by them? How much difference in mentality is there between these people and KKK members of a few decads ago carrying out lynchings? I would contend that there is not much. The current vigilantes simply happen to be targeting people who actually pose a threat to society. One particular quote on their website struck me especially. It was referring to a recent convicion they obtained, and they stated that they were dissapointed that the offender received probation, but that was OK, that wasn't their part of the system. Of course they didn't lose any sleep over the court sanction, they had already exacted their own punishment.
That being said, I appreciate the novelty and effectiveness of their methodology. I think that their tactics can form a useful component of legitimate authorities efforts at catching and prosecuting child sex offenders. I fully support the notion of identifying suspicious conduct and forwarding it to the police. I fully support developing a methodology such as this and disseminating it to police forces accross the country. I just do not support private citizens taking it upon themselves to investigate, prosecute, and punish criminal activity. A civilized society must effectively restrain criminals and monopolize the means of doing so.