Your mobile number is like a domain name. You basically own it, but some central organization provides oversight of the database of numbers. They subcontract much of that management out to the carriers, but you can take the number with you when you change carriers. Just like owning a domain name and changing registrars.
Your mobile number is linked to your personal device that is almost always with you and is already used as a 2nd level of authentication.
Why not take the next step? Use your mobile number as your personal identification on the network. Merge the idea of a domain registrar and hosting company. Instead of having to create a new account, password, and giving out your email address each time you sign up for a new online service or download a new app, just give them your mobile number. That new service/app then uses the number to query your mobile number host, and you choose what information to pass over to the service/app. Eventually, your mobile number host has an app that you install, and every time it gets queried, it notifies your mobile device and you can decide what information to allow it to access.
We take back control. Our contacts become just a list of mobile numbers, and as long as we’ve been confirmed by the other person, our apps read the current info from their database in real time. Calls get intermediated unless we’ve already confirmed that number. We create competition in the mobile number host space based on security, cost, and service. Social networking, texting, and VOIP become protocols. We win.