At that age (14-16 or something) it's normal behaviour.
Later on, it's only disturbed people who act that way.
However... The juridical system of this country is so lame that if people like that threw stones at my pond, and I hit them, I'd probably go to jail or pay hefty fines.
What law does give me right to, is 'motivate person to stop abusive behavior', thus, if someone mugged an old lady, I'd have to 'motivate him to surrender to police'. Motivating does not include beating them to half dead b t w
It sickens me too how this is nowadays, that criminals have more legal protection than normal people.
-M