We are currently trying to set up a startup that sells a software product online. The software can be downloaded worldwide and paid for via Paypal. Our company is a limited liability company based in Germany.
We recently got mail from a US attorney stating that we are infringing a patent they own.
The patent in question covers a process commonly used in software products and depicts a simple backup scenario. (More here: Prior Art for Onsite backup for internet-based data processing).
Our feeling it that it is a classical example of a patent troll and that we might want to wait at least for the SHIELD act.
The interesting thing is that in Germany that kind of patent does not exist (for some very good reasons I guess).
We are not dependent on the US market and could block US visitors from entering our site. But would that be enough? What is the worst thing that could happen? Any advice on how to proceed would be great.