Parents need to teach their children that video games are only games and the thing that are done in the games are things that can not be done in the real world. Video games have more violence now than usual, but the parents should teach their children that violence is not the way to solve anything. Majority of the young parents accept the violence video games because they themselves grew up with those games and they want their children to go up with them as well. The old generations didn't grow up with video games and the new generation is.
The factuly and staff of the school can also prevent violence, because just as much as children are with their parents they are with the factuly and staff at the school. When a child does or even makes a gesture its up to the factuly or staff to put a stop to it. If the factuly or staff does not put a stop to the bad gesture then the child is going to think its ok and he is going to keep doing it.