Easy Fix
As US Law States, you can gamble in any state provideing that state allow's it! Indian Reservations are a Sovereign within the boundreies of the US thus with state approval they can gamble on there land, with that said IF you live in a location where gambling is allowed then you theorectically could gamble online, if you do not live in one of those locations then you cannot, IE the gambling is taking place in a location where its not allowed, it has nothing to do with where the money is located, where the server is located or anything of such, it is based on the person whom is making the bet. the US will just change the law to allow US compaines to run servers from there casino's if it become and issue as stated above, though this would do not good as whos going to sit in there hotel room and gamble on the computer when they could just go downstairs to the casino floor! so US compaines would probly get a lot of the business and taxes would still be paid.