[amalcon]

There are a couple of other angles you could work here. In some jurisdictions, it's possible to seek damages for the cost of defending a failed lawsuit. I don't know if any of these jurisdictions extend this to patent litigation, or what tax and other implications might be of incorporating there (so that one might legitimately change venue to such a location). The two typical problems with this approach are getting into the right jurisdiction and being able to front the money for the defense in the first place.

Also, if the patent troll is suing a bunch of companies you're insuring based on the same patent, you could attempt to combine the cases, thus consolidating the defense costs. This works because patent trolls work by firing off lots of very similar lawsuits, each for a small enough amount that it's economical to settle. That's what keeps their costs down; such an insurance policy would let the defense leverage the same economy of scale.