I've wondered for a while about doing something similar for authentication. 1) Visit a new web app, click Sign In 2) For a moment, your webcam turns on (some

I've wondered for a while about doing something similar for authentication. 1) Visit a new web app, click Sign In 2) For a moment, your webcam turns on (some UI clearly telling you so) 3) Your photo is taken and compared to millions of tagged photos on Facebook. 4) System determines that you are indeed John Smith[1], due to the fact that dozens of facebook users (with similarities in their profile such as age/location/college/etc.) tagged someone that looks just like you as "John Smith." Therefore, the wisdom of the crowd (as measured by previously created and tagged photos on Facebook) have determined that you are who you say you are. Zero-click sign-in. [1] One teeny tiny issue: maybe you're not John Smith but just some guy with a printed-out photo of John Smith :-) In any case, I think authentication is a fascinating area that needs some attention. It's really hard to create a not-easily-breakable-or-gamed way of determining that a person is who they say they are.