In a previous life I was tasked with having to read and review letters that came in to us from the trolls. It really was an eye opener about how big a scam this stuff is.
In one humorous case somebody threatened us with a patent that was a weak improvement of a patent we held and described the product we were selling (and this was referenced in their patent). Though our patent was BS (as virtually all software patents are), I jokingly suggested to our lawyer we should sue the trolls as their trolling infringed on us.
He just laughed and said there is no point as they will have absolutely zero attachable assets, and that is why the game works.