In South Korea, computer games and movies are often guilty of making kids more violent. Recent culture trend here is to glorify gang leaders. Friendship in the Korean language sometimes means loyalty to them. Violent computer games are also partly responsible for the widespread powerful computers and broadband connections in South Korea.
Personally, I think even rifles for hunting and gas guns for personal safety should be banned in South Korea. Humans I belive need to be tamed a lot more. About what happen in the US, too complicated to judge.