FrontalMonk
Banned
Did that ever happen in ME3 though?
It didn't for me, but I think a lot of that was because you couldn't really see what someone was using beyond their class until you were in the game. I don't know, I've just learned to never underestimate the typical internet user's ability to be an asshole.
Edit: Also, a lot of games with this kind of co-op gameplay have come out in the last five years. The community has probably evolved and expanded since then.