Same story here - someone from "LLS" called and left a message at my in-laws' looking for me by my maiden name (at least 6 years old at this point), left a "case number" and were threatening implausible legal action.  I have no past due debts and at this point anything that old would be timebarred anyway. I called the number to tell them to stop calling and the accented man who hadn't otherwise identified himself or the company stated they were a "law firm" and that I "could not" just tell them to stop calling.  I filed a complaint with my state's attorney general's office online.  This company is in Los Angeles.

Note: I'm listing this type as "debt collector" since that's what they're purporting to be, but think that even that lends too much credibility to this type of scam.