The US marines are trained to kill gialnt floating heads that shoot fireballs and 15 feet tall cyberdemons? Weird, that must be why they fuck up so badly every time they go to war.
Seriously though, I appreciate that the parents of the dead kid want someone to pay, but hitting the gaming industry is not the answer. The medias (TV, music, games, films) might have an influence on peoples actions, but the people they socialise with, mainly parents, have the biggest impact on how they will react with other (real live) people. Also, as stated by other people earlier, if someone is psychologically imbalanced enough to kill a friend with a claw hammer, they aren't going to "just do it" because of a game, they are going to do it because they cannot physically or mentally understand why it's wrong. The result shouldn't be banning everything and anything that might cause offence, it should be trying to make sure parents understand the importance of teaching moral values, allowing teachers to retain their authority, and let the police and relevant authorities punish/rehabilitate/treat these people properly.