Follow up: Calling the nubmer plays an "This number is out of service" message so obviously the caller ID has been spoofed. ...so we got some genuine criminals here, folks! Probably offshore.
Claimed to be from "national credit services".. after a short conversation about the law. Would not answer any questions about contact information about their company and said they did not have to comply when ask to supply their DNC policy. The person (he) decided then to rattle off with where I live. I would assume that as a physical threat...