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.
It is becoming difficult to keep personal information secret. Recently, there was leak of the details of civil servants in my country. Almost all their personal and financial information they submitted to the government for employee verification were in public domain. This information can be used by anybody for KYC.
No one want to pass kyc with there own personal documents that's why many re try to use another person documents by browsing or bought from black market. there is no problem still a casino site thik it as subspecies. They run into trouble when a casino site wants to freeze funds and verify documents when someone keeps depositing and withdrawing huge amounts of money. If the documents cannot be fully verified then they are restricted
If someone doesn't want to pass KYC with his personal information, then he should search for non-KYC casinos or quit gambling. Using another person's details is against the Tos of most casinos and is also a criminal offense. The casino has the right to sanction the account based on their rules.