Board Thread:Support Requests - Community Management/@comment-26818590-20160402012820/@comment-26611127-20160402013700

Yikes, that can be frustrating. You should contact staff at Special:Contact/general, and an admin on that wiki should to. Staff probably knows how to handle this situation.

You can even ask a Staff member here on CC.

For now, all you you guys can do is block his/her accounts.