You just have to look at each user awaiting approval as they occur and determine from the information provided if they are legitimate or not.
This one only matches by username, so it could be legitimate (less so on my forums as I specifically request that they register using their PlayStation Network username).
In this sort of case, I'd also look at the email address and IP address.
Firstly, dispostable is a disposable email address (Google it) so that's a warning for me. Secondly the IP address is from the Ukraine (click it to see). So for my forum at least I'd be rejecting this one.