This is probably a very european viewpoint, but I find it amazing how shocked people are by children seeing porn, but don't bat an eyelid when kids are exposed to violence on television or in movies.

The biggest example from my own childhood was WWE (WWF at the time). The simplicity of the scripts etc seemed to be explicitly targeted towards kids who would then, predictably, try to copy the wrestling moves on their friends.

It's a million times more harmful than seeing the human body sans garments.

Obviously there are specific types of porn that I'd be mildly concerned by my child being exposed to, but generally speaking it's the violence and inherently problematic power structures within that are the fundamental issue, not the nudity.