I was confused about the level in the violence chain it would lie at, but I voted no once I saw the word "directly".
Video games are, just like all forms of media, designed to invoke many different emotions in its players, including anger. All violence stems from anger, but not all anger will sprout into violence, persay.
The next step in this line of thinking is the degree that video games can incite anger. This is one of the reasons I do not like the online multiplayer age, because it is inherently capitalist in nature and by definition, will screw over a lot of players. It is easier to cause frustration in video games than in most other forms of media, and frustration is a large cause of anger. But video games also provide one of the better methods of treating frustration, and this is particularly true for games like GTA. Face it, when you can take out 50,000 random people with a giant arsenal strapped to your back and you got the army after you in your pickup truck, and you're still shooting, it's hard not to laugh at the sadistic humor of it all.
Above all, however, I feel that the reason some people simply go out and take their anger out on others, is simply because they don't have the mentality to take it out in the form of challenge. You see this other characteristic in boxers, soldiers, mountain climbers. Only recently did I start taking out the frustration of my life in the weight room, and my growth has been phenomenal since then. The people who use their low moments to push themselves are the ones society admires the most, we simply love the coming-up-after-falling-down stories. Unfortunately, it's becoming increasingly harder to teach that quality. Are video games a cause of this? Yes, but not to the extent that the media makes it out to. Music, movies, etc. are all guilty of the same crime.