Also according to this article: "... Mothers Against Violence in America, a non-profit group dedicated to preventing violence by and against young people, organized its own sting earlier this year, sending children ages 12 to 15 into 17 major retail stores in the area. Fifteen of the stores sold to the children and teens."
So it seems more like the plaintiffs should go after the stores that sold the games. Unless the parents themselves bought them in which case we really know who to blame. If fingers really need to get pointed any more in this case.