How much violence is OK for a video game?

[i3670]

You can make a game about child porn, but you'll have a rough ass time trying to publish and market it. The only people you can sell it to are pedophiles who'll get arrested for buying it since it's against the law to own pornography with actors beneath the age of 18.

Basically the flaw is that child porn is not socially accepted, whereras the gunning down of imaginary civilians is, by the majority that is.