I'm not really afraid of porn. That can be handled by talking with the kid. What I'm afraid of is the kid watching one of those awful NSFL videos. It'll eventually happen, but the later, the better.
And yet, there are videos out there I wish I never saw. I gained nothing from seeing them and they only made me feel... awful about. Nowadays I just refuse to see them. But I wish I could erase them from my mind. Of course we can "handle" them. But I wish I never saw them in the first place.
I'm 40 and what are you talking about? I've... seen stuff on the internet, but I think nothing my 15 year old self couldn't handle.