Probably from their IP address.they list a whole bunch of states where you cannot play from, how would they know?
so its not worth entering for some of us then.Probably from their IP address.
I presume you cannot enter if your in that state, But IP address is incorrect as i registered to Stars when i was in the USA but under my UK address so played the UK freerolls not the USA ones. Im guessing they check from the details you provided to the site.