Do computer games lead to aggression?

We had a lunch discussion on that topic this week – of course, investigating the computer of a person running amok will reveal some (Counterstrike type) games due to his isolation. But such games are also on million of othercomputers who do not run riot and who get relaxed by playing games.
Nevertheless I read this week about the aggressive behaviour of teens who were not allowed to play the whole night World of Warcraft. So, there seems to be clear links of aggression and some kind of games. In case you are searching for references, there is a German dissertation Media violence and aggression : a longitudinal analysis of the link between exposure to violent video games and aggressive cognitions.

Both girls and boys reported regular game play, but highly aggressive boys showed a particular attraction to violent games. In accordance with previous research, cross-sectional results at T1 showed a positive relationship between exposure to violent video games and aggressionenhancing cognitions.

Another reference is “Television viewing and aggressive behavior during adolescence and adulthood” in Science 2002

There was a significant association between the amount of time spent watching television during
adolescence and early adulthood and the likelihood of subsequent aggressive acts against others.