No, I'm not talking about preference here. This is a general observation with email. It's so easy to go and get a throw-away account, which means that email is not best suited for identity as the other solutions. Sure, facebook and OAuth login suck because it gives the website you login to too much access to your data. However, not many hackers know about OpenId and that it's really cool for login. With OpenId, access to your data is more restricted, and the website doesn't have permission to access your account like in OAuth. Google's OpenID gets it right, it is possible to log in to sites without disclosing your email address, and that's how it should be.