The police have more important things to do than parenting other people's children. Take the computer away. Lock it up where the kid can't get to it. When he has a tantrum, tell him to grow up and cut the crap. Don't let the kid play video games until he can behave. End of story.
Actually, believe it or not, there was a video like this on COPS in boston no less, where cops were called ebcause a kid wasn't taking his punishment from his mom.
And cops are actually partly responsible for such things as this, the guy on the show said it himself, it's a way they serve the community, by showing brats early on not to fuck around or else they will get arrested.