Who called from 7811000000

Call came in this morning from this number with just Massachusetts as the name, left no message. First time getting a call from this number.

obviously a call center and thety hung up ?

Also just received a call from this number, I said Hello and they hung up.

Same thing just happened to me. Phone rang, I answered, and then caller hung up !!!

I just got it too, but it sounded weird.  Reporting it to Verizon.  JIC it's one of those scam calls where someone catches ahold of your number and makes tons of overseas calls.  Just saw a piece about just this thing on World News Tonight with Diane Sawyer.  Better safe than sorry.