Probably we do know more about crimes against children because of the media reports, but I really suspect there are more people who would commit such crimes than there were in past also. It strikes me that their behavior is fueled by the ready availability of child pornography. Certainly there is a connection between the two right here in our (otherwise very crime-free) little town. The police do a regular sting operation that lures child predators here. Many of those apprehended have been regarded as respectable citizens, but most have been found to have been accessing child porn on their computers.
My interpretation is that they were always pervs. Now they are busted pervs thanks to the internet.
Remember that many of the cases of child molestation by priests/preachers etc occurred during times that we remember as being 'safe'. Turns out they were not so much safe as covered up. Respectable citizens indeed.