I have a suggestion how to ensure each person receives only one stake of XEV coins. I said person, not member, because many people have more accounts which is not forbidden here, but this is a problem for a project like Nevra, because some people will try to enter more times and you will not be able to find all of them, no matter how many rounds of checks you make.
My suggestion is that each person needs to write his bitcointalk account name on a piece of paper and take a photo with it while holding his ID card with his name visible.
What do you think? These photos would not be public but developer would be the only person to see them and store them till the end of distribution. There comes the Trust aspect of Nevra.
Forget about it. It does not work. First of all it is violate principles of cryptography and second one you can buy photos in the web, it is not expensive.
But can try to limit them to minimum possible.