Why would you use this instead of login with Facebook&#x2F;Google&#x2F;Twitter&#x2F;etc., which only requires two clicks from most users and actually has better privacy implication since the user knows which data you can access?<p>Or maybe the goal of the service is for web sites to surreptitiously get more data from users who are otherwise unwilling to provide it, but are somehow willing to provide an e-mail address tied to their real identity?