I think these kinds of casinos do have a "know-your-customer" policy that is why they are asking for personal information. Probably the country they are operating in or their license requires such policy. But generally, if you do not agree with their rules, you can always move to another where they have lax rules regarding identifications.
exactly! some sites really requires its customers to have KYC first before you can make withdrawals or any other transactions. i have once visited the site, i just forgot its name and i tried to register. upon registration, it already required you to put and verified your contact number. your address and other information. i think they do this for them to know more whose really playing in their site, in short for profiling purposes i guess.