First, get a patent lawyer and try to judge how likely you are to be sued. An experienced attorney might be able to see a pattern in their behavior that you do

First, get a patent lawyer and try to judge how likely you are to be sued. An experienced attorney might be able to see a pattern in their behavior that you don't, and give you a better idea of what your risk is. Note that this risk is not purely a matter of facts -- you might well not be infringing or their patent might seem obviously over-broad. The real risk is the cost of a lawsuit and litigation, which is a combination of distraction and expense that can easily kill a small company. Secondly, keep an eye on the patent troll's behavior and on the response from your competitors. If you are friendly with your competitors, see what info you can dig up about the patent trolls. See if you observe the trolls speeding up or slowing down. You might find that a "big" settlement wasn't as big as you might have guessed. Thirdly, don't panic. There are patent trolls in every industry. I was sued by one once -- for a zero-revenue side project -- and it fizzled, but I worried a lot along the way. If they haven't tried to contact you yet, your time is probably better spent developing your business.