For various reasons, casinos have to keep track of their clients. First and foremost, they want to know if you're of legal betting age. The last safeguard is to keep an eye out for identity theft. It is thus necessary to send digital images or screenshots of some papers.
Bettors can do this on your account's verification page. In addition, you risk losing access to your account if you don't authenticate your identity. The new European Anti-Money Laundering Directive ensures that new standards for combating online crime efficiently will stay in effect.
The casino may request further paperwork, but this does not mean you are suspect; it is merely an automatic procedure triggered by your request. As a result, you can be certain that your gaming experience will be safe and secure as long as you cooperate with the casino to make it so.