One reason is because it deflects attention away from themselves. I mean, look at the news: teachers, doctors, lawyers, plumbers are being busted for CP, so wouldn’t it make a good survival strategy to be this macho moral fag who acts like he’s the knight defending children?
I mean, as much as hate pretentious, obnoxious moralfags, the opposite behavior would be pretty dumbass. A good thing to do is shut up (about things drawing in suspicion), but why stop there? Why not go for Facebook memes calling for ritual stoning?