What I was pointing out was that there was a confirmation of some sort presented to the user that indicating something that personally identified them was being

What I was pointing out was that there was a confirmation of some sort presented to the user that indicating something that personally identified them was being shared. Stack Overflow does take a "full name" (in OpenID attribute exchange terms) as a user name if provided by an OpenID provider, though we explicitly don't demand it (it is not "required" in AX terms). Exactly how a provider deals with "optional" attribute requests is up to them, in practice I think most everyone ignores it unless it's also public information on their service (ie. full name == user name). Offhand I want to say Facebook is the only login option used by > 5% of our users that provides a name. I did not actually confirm that by testing, just working from memory. You are correct in that Stack Overflow never displays user emails during normal operation, excepting employees and moderators (who are bound to an agreement before accessing such information: http://stackoverflow.com/legal/moderator-agreement http://stackoverflow.com/legal/moderator-agreement ). Disclaimer: Stack Exchange Inc. employee