my opinion is that you would have no right to tell them if there was pornography on the kids computer. Unless it was illegal material of course. Otherwise it's a grevious (to me) invasion of privacy even if the kid is 14 or 15 years old. It's just porn, he is discovering his sexuallity.
You tell his folks and if their reaction is then to take the computer away from Junior then it would be unfair (imo) to do so. The Kid needs it for recreation, school, communication etc. So what it there's a dirty picture. I bet if you brough tin 10 computers from American 13-16 year old kids you would find a lot more graphic things then women exposing their breasts.
Even then I wouldn't dare to assume it was my job/duty or anything to impose my morality upon a random teenager.
