there are measures to prevent minors from looking at porn it's called child restrictions. Most IP's come with Parental controls as standard, so again it's down to the parents to make sure they're active. My IP has parental controls as it stands I have general access but that's because it is my parents choice to trust me not to look at porn, and I don't. My little sister has parental controls active so that she can't access various sites. Other than that parents have to be more vigilant as to what their children are loking at.