[Ryoku]

This is idea makes my shoulder surfing senses wet. Seriously, it might sound like a good UX idea in theory, but lets go to practice: People are not going to use that button in the safety of their homes. Why? Because they don't care. It is not a secret that the average user doesn't give priority over commodity to security; that's the basic principle behind no-tech hacking.

The best UX experience collides with the best security experience, we need to find the middle point. This is not the middle point. Passwords are now broken from concept, that's why we are evolving into two factor authentication. Making a broken security method easier to crack (even if it may only happen when certain circumstances are met, like doing it in an airport of coffee shop) is not the way to go.