To make everything clear:
I don't know the username of the user who registered with username "niger" some hours ago and I would like to never know it, because I do not want to "discriminate" in the future the user who did that. I am just sure it was a false registration because the user was not connecting from Niger and already has an account here.
I do not want to lose time checking who is the user who did that, but of course I will have to do it he/she will try again. So I am sure that if this user is reading this, will not try again to do that
As a general rule, don't do that because you will always get caught