The age of kids does is not my concern. It's the maturity level. If people aren't mature enough to handle the game, then they shouldn't handle it at all. I've heard twenty-three year olds scream in the game.
You seem to be using little kids as a scapegoat because of the poor community Xbox Live has. True, there is a lot of annoying little kids on Xbox Live but I find the older assholes much more of a bother. But nothig stops anyone from muting anyone, Bungie's best addition to Halo 3 was the quick mute. I find this thread ironic because you're under the USRB rating's recommendation, although I'm pretty sure around 50% of the Halo community is but w/e, I don't like to be judged by my age or sound of my voice so I don't judge them.