In some cases companies are not allowed to report on certain events happening, e.g., the US Government requesting to hand over customer data. My understanding is that some companies tried to circumvent this by issuing periodic negative reports. Something like "we never received a request to hand in customer data". Missing such a periodic negative report signals to the public that the company did receive such a request in the meantime.

What do you call this "periodic negative report"?

  • Heading them off at the pass? Commented Mar 18, 2022 at 14:49
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    A little off-topic, but keep in mind, there is no reason that a government could not secretly order someone to keep posting their warrant canary, especially if they believe that discontinuing it would tip off suspects in a criminal investigation. So, whatever we call them, they probably do not reliably work.
    – Davislor
    Commented Mar 20, 2022 at 6:45
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    @Davislor Oh yeah, the topic itself is a can of worms. I specifically formulated the question so as to only ask for the term. Otherwise, we risk getting into a really long and controversial discussion. :) Commented Mar 20, 2022 at 15:40
  • Could you clarify "… companies are not allowed to report on certain events happening, e.g., the US Government requesting to hand over customer data"? As it stands, that's mostly impenetrable. Commented Mar 20, 2022 at 17:47
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    @Davislor at least in the US, the government ordering speech like that is generally going to trigger a constitutional challenge (first amendment and all) and would likely end up having at least the effect of inadvertently disclosing existence of the request. Compelled speech usually has stringent constraints and forcing a company to lie is a pretty high bar. But this is all really discussion for Law SE, and one's already there.
    – bsplosion
    Commented Mar 21, 2022 at 22:28

2 Answers 2


You may be thinking of a warrant canary. It's described by Cloudflare as

a statement that declares that an organization has not taken certain actions or received certain requests for information from government or law enforcement authorities. Many services use warrant canaries to let users know how private their data is.

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    What a cool phrase. For non-native speakers, the metaphor is "canary in a coal mine", where miners reputedly used to keep a live canary in a cage underground so they could tell when poisonous gas was getting into the air. When the canary dies, get out of the mine. Commented Mar 18, 2022 at 15:14
  • It's important to remember that there is precedent (in some jurisdictions) to require the organization keep up a warrant canary, even if it's no longer true. Thus, though slightly more hardy as a policy, they are far from perfect. Commented Mar 1, 2023 at 20:58

This is also known as a dead man's switch, in that it is activated by lack of action rather than an affirmative action.

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    Hi, kalzen, welcome to EL&U! This is a good metaphor; if you can, expand your answer a bit more (you could include a copy of a few of the pertinent sentences of the linked wikipedia article, for example, or a quote from a story or news publication where this phrase is used in the way that OP asked for). Do give some time to the tour when you can. Cheers!
    – Conrado
    Commented Mar 19, 2022 at 14:47
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    A related, but quite same, term is "failsafe". Commented Mar 19, 2022 at 21:01

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