Parental Responsiblity.
How about parents who think their child might be being harmed by the video games they play ... actually do some actual parenting. Require your kids to get approval before they can play any new games ... if you catch them playing games you feel is harmful take away their game systems.
If a kids parents can't be bothered to take an active interest in their child's life ... then that kid has a lot bigger problems than violent video games.