I set up Tasker[1] with a profile to reject incoming calls if the caller is not in my contacts. As an individual, that or DND settings are most effective.
Consumers as a group can contact regulators or legislators to urge this be fixed. The technological fix is not that difficult: telcos should whitelist numbers for specific customers so a customer can only use a number as outbound caller id if they are assigned or have otherwise validated the number. Reputable providers like Twilio already do this. This solves the oft-repeated claim that there are legitimate reasons to "spoof" caller id. You can't say it's spoofing if it's your number and you're the one calling...
But telcos don't do this. They don't care if caller ID is accurate, because their customers don't care if caller ID is accurate; most pay for it anyway.
Consumers as a group can contact regulators or legislators to urge this be fixed. The technological fix is not that difficult: telcos should whitelist numbers for specific customers so a customer can only use a number as outbound caller id if they are assigned or have otherwise validated the number. Reputable providers like Twilio already do this. This solves the oft-repeated claim that there are legitimate reasons to "spoof" caller id. You can't say it's spoofing if it's your number and you're the one calling...
But telcos don't do this. They don't care if caller ID is accurate, because their customers don't care if caller ID is accurate; most pay for it anyway.
[1]: http://tasker.joaoapps.com/