[vollmond]

99% of the phone calls I get from unknown numbers are some combination of scam/robo/or just immediate hang up. The only exceptions tend to be businesses responding to my initial contact (eg, trying to get a plumber out to my house), in which case I will answer unknown numbers for a day or two until we connect. Otherwise nope.

This is a US mobile number that I've ported from carrier to carrier since the mid-00s. Haven't been particularly careful about where I use the number, which is probably how it got this bad.

[jrockway]

I think they're just enumerating the entire address space, rather than buying your phone number from somewhere. But I guess I have no evidence to prove this; I have given my phone number to companies, and I get a ton of spam calls.

[dvtrn]

I think they're just enumerating the entire address space

Even when you consider most calls now for SIP/VoIP platforms (which is where a lot of these scammers get their DID/phone numbers from) are charging fractions of a cent for outbound calls, enumerating and then dialing entire NPA spaces gets prohibitively expensive after even five minutes of dialing waiting for someone to pick up, even for the most dedicated of scam call centers.

Doesn't mean they aren't dialing randomly to see who picks up, just I doubt they're dialing entire phone number spaces wholesale.

What can be observed going on is these scammers quite literally trade lists of leaked phone numbers and email addresses and they actively keep track of who responds, and who falls for their scam before sharing the list with others.

Jim Browning (a popular youtube scambaiter and infosec pro) has videos where you can watch it happening with your own eyes.

[sdenton4]

My partner and I have adjacent phone numbers (x and x+1). /Occasionally/ we get sequential spam calls, where my phone goes off immediately after she hangs up. But not super often. Though one can shuffle before calling everything, just as easily.

[refurb]

It’s like a war games dialer 40 years later.