That's very true. It's the freedom vs. chaos dichotomy that all societies have to struggle with at one time or another. As for pedophiles, I believe this is the domain of real world social services. Abuse doesn't occur in a vacuum and there are always signs to look for, both in schools, with friends and the local neighborhood.

Of course, competent workers in social services and an adequate budget in this field are other troublesome subjects, but I do believe no crime takes place online without a real world component. Therefore, there should be real world clues to follow.