Unknown caller. They have continually called my young daughter's cell phone, often multiple times per day. I answered once and there is no one there. I attempted to call them back and got a fast busy signal. I have no idea how they got my daughter's number, but this is ridiculous.
This number has called me at least once a day for the last six days; usually they hang up as soon as I answer, but once they answered and it was some sort of salesperson (I don't remember who they said they were).