Technically, you always created an account when you used Persona. Sometimes with a password, sometimes without. Sometimes old passwords would come back to haunt

Technically, you always created an account when you used Persona. Sometimes with a password, sometimes without. Sometimes old passwords would come back to haunt you if your domain added and then removed support for BrowserID. Sometimes you would accidentally set up two accounts, because you added a new address to the Persona UI in the wrong order. Sometimes addresses would mysteriously bounce between Persona accounts, because we updated the address/account association on each use. Sometimes you needed a password and sometimes you didn't for the same address, because we supported un-decentralizing Persona on a per-website basis. ...the account story in Persona was way more complicated than it should have been, mainly stemming from the notion that per-login email confirmation loops were too onerous to be viable, and from the idea that users wouldn't succeed with Persona unless it remembered and displayed all of their email addresses in a consistent, persisted account chooser.