Teenagers are, and always have been, and always will be, idiots. It seems to take them a long time to understand that attracting the attention of the police is no way to get ahead in life. The civilians who confront these kids are wasting their time. A simple call to the cops would have got rid of those kids in each instance.
On the other hand, you have to wonder about the parents who see their kid go out everyday with his skateboard for hours and don't care what he's doing.