For more (and better) counter arguments, start with this thread (which was about one particular comparison with Facebook Connect: possibly click to see the parent for context) and then follow my chain of earlier comments I link at the bottom of that one (which were more general, going into the flawed assumptions in Persona about email).<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=7243172" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=7243172</a><p>(By the way, I am going to try to avoid wasting even more of my life arguing on Hacker News about the benefits or lack thereof of Persona, so I am dropping these links here to maybe seed discussion among others, but I am going to attempt to avoid ruining my Christmas Eve by forcing myself to never look back at this particular thread again ;P.)<p>Also, for anyone wondering if I have anything credible to say on this subject before bothering to read any of this--and maybe to the one person who downvoted me from 3 points to 2 points, which I noticed as I fleshed out the &quot;I will hopefully leave&quot; message ;P--I have run a service with tens of millions of users that <i>only</i> uses federated login (though accounts are optional, so I &quot;only&quot; have just over ten million accounts on file), and have been staring at this space since 2001, when Microsoft announced Passport (at the time, I even was thinking of starting my own single-sign-on service, but was a naive college student ;P).<p>(later edit: I found another old thread on this subject that I am going to add here as an edit, mostly because any other way of adding it might cause me
to see if there are any responses to this comment ;P. At the time, to this new link, there were two responses I hadn&#x27;t bothered seeing and responding to: one from someone who insisted upon comparing the fundamental bug in Persona with an existing &quot;worst practice&quot; (as opposed to any of the better alternative options), and one who seems to be in left field assuming the value of a Facebook account is based on whether the user updated their email address: the point I was making is that Facebook isn&#x27;t actually tied to email addresses, as they &quot;understand&quot; the problem inherent in relying on them for anything, and so users do not run into any of the issues that Persona not only doesn&#x27;t solve but actually makes worse. Regardless, yeah: even without reading any comments from today I am  already spending way too much time at this ;P.)<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=8250301" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=8250301</a>