Re:Twitter says an attacker used its API to match usernames ...
by netsharc on Thursday February 06, 2020 @07:54AM
(#22255616)
And sadly for him, it doesn't matter anyway, presumably most if not all his friends already uploaded their address books, so WhatsApp already knows his real name and phone number and network of friends...
An app (such as whatsapp) getting access to all contacts is a valid use case, even though it doesn't apply to you.