This has been the case since I was a kid. My dad told me that I could verify[0] the identity of a caller by calling back to a number that was known to belong to

This has been the case since I was a kid. My dad told me that I could verify[0] the identity of a caller by calling back to a number that was known to belong to the entity in question. [0]: for some level of security. My father was a farmer at that time and I know he wasn't talking about a nation state adversary ;-)