Ask HN: Help I think I'm being patent trolled
Throwaway here.<p>I've been running an online service for a while now, and I just got an e-mail from some guy saying he "just filed a patent similar to what we do and hopes there will be no 'conflict of interest'".<p>Not once did the idea of trying to file a patent cross my mind, and this really makes me wonder and worry how the patent system works. I haven't been following it at all -- I just want to build cool stuff.<p>So my question is:<p>Is it possible for someone to file a patent and then come back and sue me after their patent is granted?<p>Does this mean I should try to file my own patent?<p>Am I even in danger or is this just an empty threat?<p>Thank you for any help shedding light on this.