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Warrant canaries die quietly so their passing can escape notice. But that’s less likely to happen now thanks to “Canary Watch,” a new website that tracks the health of warrant canaries used by tech firms and other organizations susceptible to receiving a secret data demand from the U.S. government.

So what exactly is a warrant canary? Named for the birds used to test for danger in a coal mine, they first appeared in 2002 when Vermont libraries posted “the FBI hasn’t been here” signs in response to the Patriot Act, which allowed the government to demand information under gag orders. If the sign disappears, the patrons can infer something is up.

Digital warrant canaries work the same way. Used by tech companies like Tumblr, they consist of a message on a website or in a transparency report that says something like “We have issued zero National Security Letters.”

The problem, however, is that it can be hard to keep track of which companies have issued them, and when they disappear.

In response, three groups — the Electronic Frontier Foundation, the Berkman Center for Internet and Society and NYU’s Technology Law and Policy Center — created Canary Watch, which will make it easier to track the fate of the various warning signals.

First reported by ThreatPost, the website not only lists which companies have posted a warrant canary, but attempts to describe the specific threat the canary is intended to detect. (This can be a challenge since government data demands can take various forms, such as FBI subpoenas under the Patriot Act or NSA requests under Section 702 of the Foreign Intelligence Surveillance Act.)

The idea is a good one since it will not only provide notice when a canary disappears, but may help to standardize the format companies use to post a warrant canary in the first place. Right now, the companies on the new Warrant Canary site include Pinterest, Medium, Cheezburger and Internet Archive. Tech giants like Google and Microsoft are absent since they have already received numerous NSA and Patriot Act demands.

The Canary Watch site is also another reminder of the larger fight, being waged by Twitter and others, to disclose the legal processes the government is using to monitor citizens in the first place. While the government often has a case to keep the details of specific investigations secret, the tech industry and civil libertarians have decried its attempts to muzzle the very existence of the demands in the first place.