Online porn addiction now a juvenile problem.

It's pretty sad, when the biggest clientele for pornography is teens, and sometimes children as young as ten. One thing I feel is important is keeping the internet out of children bedroom's. Keep the computers in common areas in your house. It permits you to have a bit more control over where your child goes online. 

Also helpful if your child develops an internet addiction. I remember my youngest daughter one summer, she'd wait till I'd go to sleep and use the computer all night. I had to lock the room with the computers at night and keep changing the hiding place for the key. 

The other thing that's really important is to talk to your teens and pre-teens about sex and not count on school or their friends or worse the internet to teach them about sex.