6 Stringed Fingers said:
Delirious: That is indeed a problem. But it is also a parent's job to make sure his/her daughter knows the presence of internet sexual predators, how to spot them and protect herself from them, instead of banning her from the internet. (I don't think anyone wants to be raped, so she wouldn't choose that option.)
the actual risk should, i hope, be obvious to most. it still happens.
the whole sexual predator thing was indeed way too extreme to be a good example, though - it was simply the first situation i came to think of where there is an apparent risk for a conflict between the parents' view ("we need to protect our child from getting with the wrong crowd") and the childrens' ("i'm mature enough to choose for myself which persons are good or bad for me"), no matter who's right or wrong.
6SF said:
The same can be said for smoking, drugs, alcohol, sex, and other problems. Parents can show their kids the pro's and con's of each of them, and help them reach a logical decision. Of course, if the kid is too headstrong and stupid then he/she still needs punishment.
...these are better.

unfortunately, there's peer pressure. if you're a 13-year-old, chances are you'll think the cool kids (often the ones drinking, smoking etc.) at school are a lot cooler than your parents, no matter how good you retrospectively realize they actually were.
what if someone reaches the conclusion that he/she should drink alcohol because it improves his or her social life and that overshadows the cons'?
it's not
that far-fetched - many adults more or less think the very same way, but i find it hard to believe too many parents would accept that as an argument. "go ahead and think for yourself, just make sure you think
the right way" sort of takes away the point of not preaching.
still, i don't claim to have any better solution, or that parents can do much more than the things you mention. it's just there. but then again, of course most kids do survive a mistake or two...
blah blah blah, and goodnight.