[akeefer]

The point is that patent trolls are pure IP companies that don't actually do anything; they can't possibly be infringing one of your patents because they have no products. That's why they're so much worse to deal with than other companies who could be counter-sued for infringement of your patents, or for theft of trade secrets, or for something else similar.

With patent trolls maybe you could counter-sue for tortious interference, but that's a pretty hard one to make stick, or you could get a judgment rendered that requires them to pay your fees if the suit is totally ludicrous, but I'm not sure I've ever heard of that happening in any kind of patent lawsuit.