Thread:Ducksoup/@comment-24860884-20141128055413/@comment-1647694-20141128062121

This sounds like a potentially serious issue, and someone with more knowledge and experience will likely reply with a better response than I. Otherwise don't hesitate to Contact Wikia about this issue.

I'd imagine that a hijacked account would have noticeably different editing patterns.

A CheckUser request submitted to Wikia staff may reveal anything suspicious with that account, such as it being used by different IPs from significantly different locations. Although there are limitations on who can submit such a request and the reason for it, as listed on the help page.