That post still goes from the starting point of &quot;social graph&quot; and &quot;5000 users in the contact list.&quot; It&#x27;s completely the opposite of what&#x27;s the most reasonable need: say if I want to communicate using the encryption only with my girlfriend, I don&#x27;t want any of other contacts be ever seen by any server, and I can agree with her how we&#x27;ll identify each other, but we surely don&#x27;t need real phone numbers transferred to any servers, and we don&#x27;t even have to use always the same real numbers.