I'm not worried at all. Rockstar's given us a way to prevent that sh*t. You can choose which people will join you in GTA Online (found this out in a recent edition of Game Informer), and the automatching service will prioritize your friends and crew. If you don't want to play with a bunch of whiny little kids (who, may I remind everyone, shouldn't be playing the game in the first place [note to 14/13 year-olds: I have a few friends on PSN who are the same age as you and are much more mature than my 16 year old friend or some of the "adults" here on GTA Forums]), just change your online settings to accomodate for your playing style. Plus, I think GTA Online is too serious of a multiplayer game to allow for sustained child's play, so to speak. With a large focus on missions and player-created content, I think GTA Online will kind of settle into something like SA:MP in terms of a community, except Rockstar will be a part of that community (and I personally think that's why Lezlie The Benz is so excited about GTA Online; he'll be one of the players who experiences his own game, but with other brilliant players creating awesome creations from the scrap tools that Rockstar gave them).
@ 14 year-old bragging about staying up until 11:30,
I stay up until 4 am sometimes. TBH, a late bedtime is really bad for your health, and I can speak to that first hand. Because of my eratic sleeping behaviors, I sometimes get very tired at around 5 pm (right around the time my college classes and work is all taken care of), and then I'm up and at it at midnight. It isn't worth bragging about at all (in fact, most here would probably tell me to get help with insomnia or something, even though I don't actually have a problem going to sleep, but rather with getting a consistent sleeping schedule; then again, it could just be my anticipation for GTA V and I'm just exagerrating), and a bed time doesn't say anything about your maturity; if anything, the fact that you're bragging about it in the first place speaks volumes about your maturity. Maturity is more like being a good sport, not getting mad very easily, will play the game how it was meant to be played (or at least not in a way that impedes how others want to play it), and being able to handle mishaps with serenity and intellect. Your post has not displayed any of these characteristics; if anything, it displayed the antithesis of mature characteristics.