Not only casino sites but other sites can also sell user documents if it is a scam site. But the real sites and those who come to do real business will never sell their users' documents. Because it's an important thing. Which can be used to complete various types of illegal work. So real sites will never play with the security of their users
Users don't hesitate to send their kyc documents on real websites. But a website is only real until it scams users. So crypto users often think twice about sending Kyc Documents. No real website would even think about selling their customer's documents to anyone, because doing so could get them into a lot of trouble. But this website has already made their decision so it is easy to imagine that these documents will not be safe.