Report him for what, thought crime? I have thought about gay sex, suicide, robbery, rape, murder, cannibalism and yes, even fucking a child before. I can't see myself doing any of these things but the mind doesn't give a damn, it just gives me weird stuff to chew on whether or not I like it. I suspect everybody's brains work the same way. The guy decided to talk about his thoughts on an anonymous forum because he didn't feel safe talking to anyone else. Reporting him is a betrayal of this trust and undermines the whole point of this place. If he admitted he's about to rape his kid, that would be an exceptional situation but that's not the case. I don't see the girl being in danger.