If this happend in the Mobius private group. send an email to
admin@elitepve.com along with any screenshots you have to report the bugger. The admins will probably contact ThatDamnRanga to get his/her side of the story also.
BTW, you might want to edit that pic so as to blank out the identity of the attacker - it's probably considered naming and shaming.

Edit: I just caught up on some other posts. Currently, Mobius isn't able to add or kick members, and it appears that Deathgrips and others are taking advantage of this to wreak havoc.