Yeah... Kids throwing rocks is something new to me as I am a foreigner. I think it is not parents fault, parents, most of the time, don't even know what their kids are doing. It is more likely a society's fault. I don't want to thrash Irish culture, but if the kid threw a rock to a car in Lithuania, a driver or other people around would catch the kid and seriously kick his ass and bring him to his parents, would not call a police, but would demand parents to pay for a paint job of the car.
How do I know? I was one of them kids... However, I threw an apple to a Mercedes Benz once... Got a good beating and had never thought of throwing anything else again
Kids are too brave in this country, cause they know they can get away with anything. They have to be a little bit afraid of elder people and have to respect them.