Called ID said "Unknown Name".  It looked identical to the number of a business I recently called except for the last few digits.  I thought they were returning my call, so I called back.  Upon calling, a message answered and started blabbing about saving on life insurance, so I hung up.  I'm sure these scamming pieces of crap will call back over and over again now that I called back.  My rules is to answer and immediately hang up on unknown callers to give the impression of a bad connection, which is what I suggest others do.