Who called from 3100000000

San Diego Sprint customer...

I've recieved 3 calls from this number in the past 3 days. I answered twice, and what do you know? The call disconnects. It's pretty suspicious, and I'd like to know what's going on.

Don't say anything, hit mute.. someone will answer after a while.

I got 3 phone calls in the last two days, and every time I pick up they hang up.  I have verizon; I don't state a political party, and I live in San Diego, CA.

I have had the same problem, 5 calls within 24hrs.  I answered last night, but it hung up.  I also live in San Diego.

same thing here, every 6-8 hours I get the call for the last 3 days.  I'm in San Diego.