Less Child molesters, less crime.
The problem is, they should have been executed, not turned loose.
This guy simply did a job that American Justice won't do.
I don't shed any tears for the sex offenders, but the big risk here is the possibility of mistaken identity--happens often enough that the police get the wrong guy, and they're presumably better trained in investigative techniques than your average Joe Sixpack. Hate for an innocent person to get whacked because some data entry operator keyed in the wrong address in a database.