Which is why the legal system is an utter failure.
Patent trolls play the probability game which usually results in a net gain because the legal system is failing.
I would say that there should be laws against this but that will result in another loophole or way of making money.
Perhaps I'm a socialist wierdo, but I'd favour scrapping the entire patent process for something which rewards positive contributions to society as a whole rather than who can screw who first. People should be creating things that improve the human condition, not enslave it.