If the casino is in the jurisdiction of the countries whose laws regulate cryptocurrencies, they also at any time may require their customers to pass the KYC, even if there is no such requirement when registering an account. That's why you should be more careful when choosing a casino and be ready to provide your personal information at the first request.
or you can opt to gamble only on casinos that have no KYC or descentralized ones
i'm surprised we don't have more of this kind of application running on ethereum and sidechains these days