I agree with Angel, something is wrong, it is disturbing, report the behavior. Having that many photos of children, who are not consenting to photos being taken, is still illegal as indievisible said.

I also agree with Angel that more likely than not, they can't be rehabilitated. He spent 10 years in a hospital and did he stop the behavior? No. He is still downloading photos of children and using them as a means to become aroused, be that mentally or physically.

You can't fix him, it seems no one can. Keep yourself safe because since you're sharing internet, if that is under your name, you can catch yourself in trouble to and you haven't done anything wrong.