HAHAHAHAHAHAHAHA! I'm adding you to my friends list just for that comment.
That is not stupidity just a part of immaturity. Being immature is not a negative just a part of growth.
Those who claim the kid deserved it are stupid or maybe ignorant. The equivalent is yelling at an 8-year-old and expecting them to act and think like adults. It is your expectations that are unrealistic in both cases.
When I was 11 I wouldn't have done something that stupid.... never mind 15.