These calls are only prompted when something looks suspicious like many different sign in locations or if you use a VPN. They ask for personal info like Ace mentioned plus maybe how you deposited, what your ISP is. They want to make sure it's you. If you use a vpn they might ask you to turn it off and request a withdrawal with your real ISP/WIFI.Usually all they want to do is verify some information to make sure your account didn't get hacked. Typical info they ask for is DOB, address, email, last bet you made etc.