This doesn’t work if you’re on-call (and don’t have a very specific set of numbers that calls could be received from), run a business, looking for work or awaiting vendor calls.

Now, do I charge my employer when I get a scam call on the work phone while I’m on-call? Technically I should.

Also doesn’t help that callerids get forged to be similar to your own number, which looks like the corporate block of phone numbers we have. Tho I think the networks have someone cut down on the ease of doing that (or at least tagging them as likely fraud).