There are multitude of reasons why a gambler may be banned in a casino. Whether it is because of suspicious activity or misconduct, the casino doesn't just ban or restrict a gambler for no valid reason. But it seems like these restricted gamblers have found a way to still gamble. There is a group of people who would "borrow" the identity of others to continue betting. They would use other people's identification documents such as passports or driver's licenses. They would give it up once the rewards have been collected.