A couple of weeks ago, I turned off Persona on ReqFileCheck.
Persona was a login technology for websites that allowed users to easily login to any site with Persona enabled without having to create a new password for each site. It was created by Mozilla (the company/project behind Firefox), but they passed it to "community ownership" and are now shutting down the servers that run it in November this year.
It worked really well for ReqFileCheck, as the site uses the validated email address to send the alerts and authenticates the users to update their requirements files. As a neat side effect, it was possible to switch between users (email addresses) very quickly, and I used it to great effect having two emails in the same Persona account, having separate sets of requirements files. Now the site uses standard username and password auth and I have to logout and login again to switch between the email addresses, which is much less convient.