As long as everyone is playing nice, I don't care. That said, unless the parents have determined that their child is mature enough to handle it, I don't believe that younger gamers (exact age of "younger" depending on the rating of the game in question) should be allowed to play games that are rated above their age. Unfortunately, I don't trust most parents to intelligently make that decision. In my experience, most parents these days either don't parent very well, or don't at all. Either way, you'll find just as many...unsatisfactory...people between the ages of 17 and 70. Honestly, I was more mature than some of these people when I was 4.