Of course I've encounter them all the time. I just find their name quickly and tell all the people that are too stupid to figure how. Then tell everyone to report. I have problems with those that use them in PvP, but in Coop I don't really care, but i tend to avoid those games.
and obviously other community(ies) have one, probably not free though, which I'm glad since it lowers the amount of idiots running around with it in public.
I've also heard that people just get banned ;o