If it happens once it's a mistake.
If someone or group of people are repeating it, it's an exploit, they know there is a problem and are using it to make an unfair advantage.
Roll back is the way to go for these people, or barr the accounts until game launch on the 20th.
If people were openly telling others about it in general chat, then thats bannable.
Kick em out we have lots of people waiting to join.