I don't know about other states, but here in Arizona, it is ILLEGAL for ANY business that wants/requests/demands money (telemarketers, collection agencies, etc.) to block/spoof/send OUT OF AREA for caller ID... it MUST be their actual phone number. If I get a 000-000-0000, 800/888/877 area code or unavailable/out of area, i simply pick up and hang up.
I keep my anonymous call reject on at all times.