This is just another web based open sign-in. Why did they tie this to email, of all things? My immediate thought was that a browser-based ID implementation wou

This is just another web based open sign-in. Why did they tie this to email, of all things? My immediate thought was that a browser-based ID implementation would let you keep secure credential on the computer, saved by the browser, up to and including pics, profile, etc. In other words, take social credentials native.