There are two outfits that supposedly use the DNC for numbers along with predictive diallers. (Illegal on cells)
One is some kind of survey, and the other is Card Services.
This is where those sites like Who calls me comes in handy. People complain there, which does no good, but you can find out who the caller was before adding to reject list.
I have the MID file of Cocaine for unknowns and if I hear that, I check. I've let the thing ring out just to see what will happen. They can't leave a voice mail, I've cut off the service. I've always used missed calls anyway.
I'll give you odds that the Vulcan will come down with the story again. I've told him for years to check Snopes.