Problem: How do I block scam calls and robo calls?
Premise:If the call is important, the caller will leave a voicemail.
We put every number we know into our caller ID systems.
If a number we do not recognize, or a number that blocks caller ID calls, we always let the call go to voicemail. Callers that really want or need to talk with us will leave a voicemail. If we are not interested, we delete the message.
This process initially upset some of our parents, but we have not had to deal with a robo or scam call in some time, since the calling computers almost never leave a voicemail. Our parents are now used it and leave messages. Sometimes, we pick up as soon as they start talking. Our friends mostly communicate via Facebook, internet chat tools, and email these days, so they are used to asynchronous communication and don't mind leaving a message. The political parties and charities we support do leave messages. We call them back to donate or express our support.
It's simple, effective, and free.