Totally agree. The ease of use and security implications are certainly important, but how users perceive their privacy is essential to usability (shameless plug

Totally agree. The ease of use and security implications are certainly important, but how users perceive their privacy is essential to usability (shameless plug: http://nicelycoded.blogspot.com/2012/01/signing-in-with-facebook.html http://nicelycoded.blogspot.com/2012/01/signing-in-with-face...)