My Google Voice now screens calls for me. No message left, so blocking now. These are not legit businesses, so they won't use DNC anyway. It is up to us to pressure the phone companies to deal with them. But they won't, since the scammers just pay for lots of lines, and they change all the time.
Our business receives many calls, day after day from the same sales pitch about "Google Maps...". Every one is a different caller ID across the country. I don't pick up lines from areas outsider where our customers are located. If it's important, I'll call back.