[DUMBGRUNT]

Why Phone Fraud Starts With A Silent Call
https://www.npr.org/sections/alltechconsidered/2015/08/24/434313813/why-phone-fraud-starts-with-a-silent-call

That initial call you get, with silence on the other end, “[is] essentially the first of the reconnaissance calls that these fraudsters do,They’re trying to see: Are they getting a human on the other end? You even cough and it knows you’re there.”
Company researchers estimate 1 in every 2,200 calls is a fraud attempt...

[hadaclueonce]

That initial call you get, with silence on the other end, “[is] essentially the first of the reconnaissance calls that these fraudsters do

Every Ipad like device, every Google account has phone number attached to it. There is money to be made for people to "mine" for live numbers. I bet they have a Lobbyist that pays well too.