Let me give a nice little event that happened:
I was at walmart, buying an old copy of Transformers: War for Cybertron since I missed it on release. [This was about a year after it's release] When I was looking for the game, there was a kid next to who couldn't have been more than ten. He poked the casing for the game he wanted and left, I didn't see which game it was so I minded my own business. After I found WFC, I went to get the clerk, only to find the clerk talking to a woman who appeared to be the mother of the little boy.
This boy wanted Black Ops, but the clerk warned the mother it was rated M For Mature. The boy through a fit, obviously, like normal, so I went over and did this: "You know what kid? Life is unfair. Life sucks. You don't always get what you want. Shut your whining, deal with it, and be the mature adult here that your friends clearly aren't." He pouted at me, but with a sinister "I hate you!" look in his eyes.
His mother looked at me odd and I said "Be the responsible mother, don't give in to his whining. Make him earn what he wants. Make him do something worth the games, like respect you." She looked at me a bit thoughtfully, but then her son tried to swing at me, calling me a dickhead. I picked him, and hung him upside down. I then added respecting others the kid started fussing. All the while I turned to the clerk and asked for the WFC game.
He went off and got it and when he came back, I let the kid go and he walked out of the store empty handed. When I went back to the store about two weeks later with my grandmother for groceries, the store clerk recognized me and told me the mother sends me thanks for helping.
I feel good about that experience. I know I had friends with M rated games growing up. My parents kept a firm leash on me, and I didn't get a single M Rated game until I was fourteen.