These websites are shady at best, regardless of whether you like KYC or not, when you go to the bank to open a bank account, the first thing you do is to fill that KYC application, and then they will take a copy of your passport/ID, the whole procedure is done PRIOR to depositing.
 The fact that these websites and exchanges allow you to deposit as much as you want, trade or gamble with any amount you have,  and ONLY then play the KYC card when you plan to withdraw is a clear evidence that they are counting on your inability to comply so that they can keep the money.  , if they were to force KYC upon registration many of their potential clients will steer clear.


Some of these websites operate in countries that force them to collect all of these data, also if they want to have a fiat-gateway of some kind, the bank/provider will force them to apply KYC, so it isn't really a choice.
 The funny part, however, is that many of these websites operate in countries that have little to no restrictions, so this whole KYC thing for them is nothing but a scam-attempt.


You will be surprised at the amount of people who do not mind sending their nude pictures just to roll a dice on a random online casino; proof is all of these websites’ hacks result in a tremendous amount of client's information.