I don't see why you can't just tell the patent troll to go away. Are they being punished for telling you what they do? Yes, but if patent trolls have to operate furtively, not telling anyone what they do, on pain of being denied service in many places, the world is a better place. Make the world a better place.
I don't see why you are obligated to lend a helping hand to evil that happens to be legal. I'm not saying to throw a punch at someone doing something legal that you don't like; I'm saying that you are not obligated ethically or morally to do business with them. Or if the law has something to do with ethics in your world, then consider that since it's legal to deny service to patent trolls, it must be all right, right?
And I don't see what's unethical about one adult selling another adult neuroactive pharmaceuticals, but let's leave that aside for now.
Drawing the line around what's "legal" says to me, "We'd rather not think about ethics, so we're going to draw the line somewhere defensible that we don't have to think about." In another world this might make sense, but not in a country that criminalizes marijuana and has, well, patent trolls. To respect that line, and not try to promote good or retard evil any further than that, is just an abdication of ethics.
With that said, I respect Less Annoying CRM for trying to think about the issue at all and post about it, which most companies don't. I mean, they got the wrong answer, but most companies don't even try or think at all, so this blog post actually does rate LACRM in the top 10% of all companies in my book.