[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.