there's a disease or mental condition that people have, causing them to not be able to tell the difference between fantasy and reality. that's the only problem i see in violent games: if kids or people with this condition plays these games like grand theft auto, then that might be a problem.
my cousin apparently has this type of condition, and he plays grand theft auto alot, which is my aunts fault. she KNOWS that he has this condition, yet she doesn't stop him from playing this. (my relatives are somewhat dysfunctional) a friend of my dad asked my cousin "what's so fun about these games?" and my cousin responded with "you get to kill people, it's a lot of fun!". yeahhh.... that's where i'd get freaked out and completely block out violent games for that kid.