This is precisely why iOS and Android should never have allowed an app direct access to our Contacts. Rather, everything from the API should be anonymous hashes

This is precisely why iOS and Android should never have allowed an app direct access to our Contacts. Rather, everything from the API should be anonymous hashes AND be different per application. The OS should also have supplied a "Contact list UI" that gave apps a unified way of displaying contacts without giving away the keys to the kingdom. Otherwise, once your contact list is uploaded, everyone's privacy is violated.