I used to worry about that sort of thing. Anymore, i just keep going about my way and ignore him. hell, just yesterday, he stole a pair of ww off me in uber.
Just keep playing and remorting, you have enough $ you should be able to get anything back he takes easy. Then, sooner or later you will find that you can take him. then, take vengeance. just be sure that when you DO take vengeance, you let everyone know why so he cant cry and say that you are abusing power. keep a log of ss till then.