Credit card interest rate scam.  Recorded msg said they'd been monitoring my credit cards for 6 mos, congratulations on my great payment history, and I've qualified for a zero interest rate on all my cards.  I guess they're going after two groups of people: those gullible enough to think they can get zero interest rates on all their cards, and anyone concerned that they might be monitoring their credit cards.  Both ideas preposterous, of course.