[escherplex]

Bad actors exist and they're cleaver. Plus these days you don't have to remember anything. Adding an updatable PIN field to a personal call file in such an app coupled with a software protocol with a pop-up button labeled say 'PIN entry' which appears once a contact device answers (say, with a message enter PIN) that can transmit the PIN number would be sufficiently user-friendly for such an app. Better than receiving junk calls while waiting indefinitely for regulations with teeth from dysfunctional legislatures.