Did you read this article? I mean really read it. The author emphasizes involvement, but independence. She talks about the fact that your children will need time to play on their own as well. She doesn't talk about scolding your kids when they are on too late, or interact with a situation inappropriately, but instead providing feedback and helping them to understand where things went wrong.

The fact is most of the kids I knew growing up who were "problem" children either had parents who were not involved, or who were involved in completely disconnected manners, which in no way emulates what is shown here. Parents should watch their kids, they should be aware of what they are doing, and they should provide feedback. You also jumped to the "porn" connection. You will notice that the example she linked was not pornographic in nature. It had to do with an inappropriate relationship online. Sexual content and morality is going to be established from household to household, but I would bet that your nice detached European parents wouldn't want their kids involved in say a neo-nazi group, or looking up how to cook meth in the basement. Just a guess. There will always be content that a given set of parents finds to be unacceptable, and they should be involved enough in their kids lives to know if they are mixed up in the wrong things. That is not unreasonable. You sit back, you observe from a distance, you encourage, you teach, and you allow your kids to fall down when you know they'll learn from it, but you stop them before they jump off a cliff.

I'm guessing you're a teen. Trust me on this one, once you're a few years out of college and you look back, this is going to make a lot more sense.