Thread:Sannse/@comment-26496120-20160220222548/@comment-25739558-20160220231229

"If you choose to register for membership, in consideration of your use of the Site, you agree to maintain the security of your password and identification and to be fully responsible for all use of your account and for any actions that take place using your account."

- Wikia Terms of Use

The above quote is the exact reason that the person was barred from using Wikia's services. By not taking the proper measures of security, the account was compromised, and that is solely the operators responsibility, even if it wasn't the operator's action.

As for whether global bans can be removed, I believe they can. The software Wikia uses–called Phanlanx–I believe allows for rules to be removed. Don't quote me on that though, as I have never used Phalanx.