I thought you could just turn it off in multiplayer or join games without it on?
To quote a guy from another forum -
"Seriously, I'm tired of the bitching about autoaimers in FR.
Helpful tip, if it annoys you DON'T DO IT
The only reason people are auto-aiming on you is because you're doing it to them. If you're aim control is set to Expert, they have to manual aim, too. Right now, all I see are a few babies crying about how they want the easy button all to themselves.
I'm usually on Expert unless I'm grinding the Mines, then I set to Normal because I just want XP, I don't care about skill

Though, I love hearing the voice chats with people screaming "That guy has to be hacking, I can't lock on", when I have Expert on."
So if this is true just turn it off -_-