Oh god I didn't know! That's really awful and sad...I'll admit I didn't check his profile at first, and just assumed innocently he was just another good artist with a disney interest, not that he'd be a thief.
Neverless, I kicked him out of the club and blocked his two accounts from ever entering the group. I also blocked those two accounts of his from my main page, but thankfully he hasn't watched me...I just hope he hasn't favorited anything of my own either!