Agreed that usernames aren't exactly anonymous, which is why the platform doesn't require one to use and you can share your QR Code directly instead. I think the mobile apps might force registration with user discovery (this is an active argument i've been having...) but it's not designed to be required.

It's not fully baked, but my expectation is that it will work similarly to how the .eth, namecoin, and other systems work, where you'll be able to register a user discovery service on a blockchain which the clients will recognize and use for searching. In this model, NYT registers "nyt.xx" and "rcarback" pops up in the interface as "[email protected]". As it stands, we've rolled out a basic version with a single central user discovery point for now.