Twitter has allowed the certificate for its Tor onion site to expire, effectively killing off a privacy- and speech-protecting service that it introduced last year. Visiting the Tor-specific onion site address will now deliver a warning that the certificate verifying the site’s authenticity has lapsed; proceeding past that point (which is highly not recommended) currently delivers a Twitter error page. The certification expired on March 6th, just shy of two days before the site’s one-year launch anniversary.

Twitter no longer has a communications department to ask about the change, but the Tor Project confirmed the service’s lapse to The Verge. “The onion site is no longer available seemingly with no plans to renew. The Tor Project has reached out to Twitter to look into bringing the onion version of the social media platform back online,” said communications director Pavel Zoneff in a statement. “People who rely on onion services for an extra layer of protection and guarantee that they are accessing the content they are looking for now have one fewer way of doing so safely.” You can still visit Twitter.com via a browser running Tor, but you won’t get the added benefits a Tor-specific onion site confers.

Onion sites, sometimes called hidden services or “dark web” sites, must be accessed via a browser that uses the anonymous and encrypted Tor network. (This keeps the user’s web traffic and point of origin secret, and it also lets users get around government censorship efforts like those of Russia and China.) The services’ perks include an extra layer of security and an aid for distinguishing good-faith encryption users from malicious botnets. While onion sites are far from mainstream, you can access ones for Facebook, Reddit, and several major news organizations, among other sites. Twitter, until now, was a welcome addition to their ranks.

Despite the Tor Project’s efforts to reach Twitter and resurrect the service, its future doesn’t seem rosy. “The people who built it — at least all those I interacted with — are all gone,” security engineer Alec Muffett, who helped launch the service last year, told The Verge over Twitter direct message. “I’m pretty sure that it’s going to stop working totally at some point, unless Elon takes an interest.” Twitter has slashed its headcount in multiple rounds of layoffs, including members of core operational teams, and it’s had problems with the basic stability of its main site, let alone its Tor alternative.

I’ve sadly expected Twitter’s onion site to go down for some time now. It was launched by a pre-Musk version of the company that put an emphasis on global free speech and privacy, and it probably didn’t contribute much to Musk’s current goal of boosting Twitter’s revenue. But it’s still a shame to see it happen — so happy almost-first birthday, Onion Twitter, it was good while it lasted.