Yes, this is part of the need to formally assert Copyright in the US: having registered copyright, obviously the claim needs to be available to others if they are expected to respect it. In other jurisdictions, copyright exists by default, iow you don't need to formally register your work with a copyright office to be able to assert your rights later if somebody copies. FWIW I haven't registered copyright in the US, ever, though I have pursued (and been granted) software patents. In the SAAS age I'm not sure I'd bother even with that, but certainly I'd support KG's recommendation of professional advice, hopefully from an attorney honest enough to advise against protection that delivers fat legal bills but doesn't really add much protection. ;-)