Yes!
I was playing with some guy, and he remained somewhat quiet throughout the majority of the game, all I could hear was the random cough and the heavy breathing, then he suddenly went "OMG, SHE'S A GIRL!!" and began to cackle excitedly.
Some guy on my PS3 list asked me out twice, despite me telling him I had a boyfriend and lived in England.
Having a female avatar on PS home causes loads of guys to come up to you and say "hia sexy, show us ur tits" and try to make your avatars touch in a sexy way.
I was on my boyfriends account and changed his avatar to a tall, thin, blonde female. The amount of men who came up and tried to flirt was amazing.
The best thing? His user name has David in it.
They are so dense, I'm surprised they knew how to turn a PS3 on.
Same with websites, one guy had a massive go at me because I wouldn't "cyber" with him, another one said he fucking hated me and he was going to kill me because he fancied me and I had a boyfriend.
I can hold my ground though. God help them if they met me in real life.