The only games I play online with strangers are COD4 and Madden. COD4 can be pretty bad; the best (worst?) is when someone on your team calls you a name for "stealing" their kill.
In my experience, Madden is the worst. I don't play with my mike often, but in my experience, sore losers will send text messages.
Last night I was playing Madden 10 on PS3 with "LISTERFIENE_420" (don't play with this guy; first of all, he sucks, and secondly he bombards you with racist texts). He got the ball first and proceeded to go FOUR and out on his side of the field. That's right, FOUR and out. I hate stupid players who don't play smart and don't punt when logic dictates that's the right call. Right after he turned the ball over, I got the message indicator. I thought it may be him wussing out and asking for a friendly quit. Nope, it was a racial comment on his part. Throughout the game, he sent me numerous racial messages that I found funny (NOTE: I didn't find the racial comments themselves funny, I found the idea of a guy being so pathetic to resort to this BS funny). I beat him 21-14, but the score was not as close as it seemed; I shut his offense down and held him scoreless until the fourth quarter. He got his first TD on an interception return and his second TD after he recovered a fumble from my running back in his red zone.
This guy was pathetic in his ignorance and of course, his grammar and English (there seems to be a correlation...). He used the N word multiple times, and was so stereotypical in his rants. Some of the highlights he sent me were (paraphrasing, of course, and unlike him, I can spell and punctuate correctly):
"My ancestors beat on yours, spook"
"Enjoy your welfare check"
"Why don't you get a fat white girl pregnant and skip out on child support payments"
"You'll be a drive by victim soon enough"
So sad. The anonymity of playing online allows idiots to post all the moronic and racist comments in the world. It's sad on one level that someone is this racist. It's sadder on another level that this guy, in his racist anger, assumed that I was African American, which I'm not.
So I stooped to his level and sent him a pretty explicit text about his mother and promptly blocked him, getting in the last word. Childish on my part, I know.
Unfortunately, playing online you encounter the occasional idiot.