 Two computers in the same room
I don't know how they do it here, or anywhere else on the internet, but I'm guessing you could just check that the guy is using two computers in the same room by seeing if his IP address is the same. I've heard of people being banned for playing while connected to the same router and on the same table. In fact some places don't even let you get on the same table if you're on the same IP address. |