Just got a call a few minutes ago myself.  Right before 8am. 5 second silent voicemail.  No clue.

Got a call on my cell phone about an hour ago. Didn't pick up. No message left.

Received a call. No text or voice mail left.

Got a call. No message about an hour ago.

I received a call from this number at 7:12 am this morning.    I googled the number and it says that it's from a towing company in Clovis, CA, which I'm hundreds of miles away from.  Needless to say I don't take calls from strangers that early in the morning, but thought it was weird so many people getting called today so I thought I would add my call to the list.