We all know those web pages where the only alternative to a site-specific login is a social networking account. That's not very reassuring for anyone skittish about linking their commentary to a Facebook account relatives might see, if they're even willing to join a social network in the first place. Mozilla has been aware of that hesitation long enough to have just released its long-in-development Persona sign-in service as a beta. Although it has the same kind of simple approach to a login as a Facebook or Twitter pop-up window, Persona's emphasis is on privacy: it stops paying attention the moment credentials go through, keeping any diatribes or subscription details from landing in social streams or central databases. Users don't have to play a rousing game of guess-the-username, either, as they just need to sign in with one or more familiar e-mail addresses and a single password. Persona faces an uphill battle in getting web developer adoption when the establishment sign-in services are open to hundreds of millions of internet citizens, but it does have The Times' online crossword section, OpenPhoto and Voost as early poster children -- and anything that lets the privacy-minded join the party has our vote.