A new, vastly capable, largely anonymous distribution medium and meeting place where pedophiles can display and trade their wares. I don't think there is cause to believe there are substantially more pedophiles than before, its just that kiddie porn was difficult to get and there were greater risks involved.
although, I do not look forward to the day when scores of young people will become desensitized even to child pornography as they are increasingly becoming to adult pornography due primarily to the internet.