If enough of those tiny little shell companies get wrung out to bankruptcy, there won't be any left to act as fronts for this kind of unethical, and illegal, behavior. And, if they are acting on behalf of other companies, that would likely come out in the court proceedings...which could allow taking the suit up the chain to the actual parties who instigated it. One would hope, anyway, though IP law in the US behaves in deeply irrational ways sometimes.