Keep trolling them, until death of this man.
His name isn't even on that assassination market site yet. Although even an insane but rational person would realise that Karpeles needs to live in order for there to be any chance at the return of coins.
Perhaps it will get added once people start to realise there's not ever going to be any return of coins, but fact is he's done this before and didn't suffer any negative consequences so I doubt he is that worried.