I think that playing violent computer games is ok. There is a point, though, that it becomes a lust to kill. If you play twenty minutes a day of a realistic shoot-'em-up game, not much harm can come from it. If the game becomes unrealistic in its violence (Doom 3 for example), it becomes the lust I mentioned above. For instance, you shoot someone with a regular bullet and it leaves a huge hole.
   Here is the kind of game that's ok. When it is a realistic military role playing game (RPG) like Ghost Recon, where you are fighting towards Moscow and then in Moscow, where every bullet has a realistic effect, and you play to play, not to see the gore, you're ok. In lots of the games, you are fighting against groups of men, so even if you wanted to you wouldn't have time to watch the blood ooze out from the corpses. This is just my viewpoint. I'm not saying that I am right or wrong. Everybody is entitled to their opinion, and this is mine.