[g6nhe9twPd66]

I'd like to know how you don't receive spam calls to your mobile # as the robo-dialers just go through the entire list of phone numbers in that area code, so you have to receive some to that device. I do the same as you but with Skype instead of GV, but my mobile # gets hosed by robo-dialers.

[diminoten]

Because while it's a common assumption that the spam callers do this, they don't actually do this, because while robocalling is sometimes illegal, actually dialing every single number removes any/all plausible deniability if they're ever caught, and provides little/no additional benefit.

[JohnFen]

> Because while it's a common assumption that the spam callers do this, they don't actually do this

It sure looks like they do. Spammers have been calling our office lines daily (including numbers that aren't assigned to anyone and aren't given out). The spam calls come in numerical sequence. They're clearly just working through every possible phone number, in sequence.

[diminoten]

They do that for your office (343-564-21xx), but not globally (000-000-0000, 000-000-0001, etc). There's a substantial difference.

[r00fus]

I also have carrier-based (free) spam prevention which may prevent the POTS equivalent of a port-scan. But that wasn't enough - with GV based call screening, it's now down to near-zero.