Got a call this morning (early) but I didn't pick up and they didn't leave a message.  When I looked up the number this is the info I received:
Location:TUCSON, AZ
Carrier:LEAP WIRELESS INTL, INC. DBA CRICKET COMM, INC.
Phone Type:Mobile

The type of phone is a mobile, so I'm guessing it's a scam number.
If you have an iPhone 5 and have updated to the latest version, you can simply BLOCK this number by hitting the little i and scrolling down to the bottom you'll see a block caller option

Got a call from this number @12pm.. didn't answer, and they didn't leave a message. I called number back and it was a busy signal.. So annoying lol..

Got call at noon, central time, did not pick up and did not leave message.

Called my cell at 2pm Central, left a 2 sec message with nothing said