At this point, we should really throw away the current phone system and use an authenticated model. There should also be laws forcing the phone companies to not allow this. I get at least 2 spam/scam calls a day and there is no hope that it will reduce.
Actually, there is a (small) bit of hope: SHAKEN/STIR [0]!
> STIR/SHAKEN, or SHAKEN/STIR, is a suite of protocols and procedures intended to combat caller ID spoofing on public telephone networks.
> ...
> As of 2019, SHAKEN/STIR is a major ongoing effort in the United States, which is suffering an "epidemic" of robocalls. The Federal Communications Commission is requiring use of the protocols by June 2021.
