-snip-
Good points.
However, they're not only checking by themself but with the help of their provider. In my speculation, the provider can be stored how the user activity until now everytime there has a problem for some like this most of the time always from sports bet players.
Meanwhile, my self playing livegames withdraw more than a thousand dollar don't have a problem comparing to some sportbet while get caught and their fund got lock who are deposit 150 or 200$.