[trentnix]

Hopefully someone more educated than me will chime in, but inevitably a C&D or some other lawyer letter will reference law (for me, it was trademark law) or will reference a contract. I've gotten both kinds, and found that it was easier to educate myself regarding the threats made in reference to the contract than in reference to the law.

Once you do some searching you'll get a better idea of whether you need legal counsel. And just because you receive a letter doesn't mean you need to respond no matter what absurd timeline the demanding letter might have suggested.

Eventually they'll have to put up (and file a lawsuit) or shut up.