What is Warrant Canary?
A method by which a service provider can inform users that they have NOT received a secret government subpoena. If the canary statement is removed or not updated, it signals that the provider may have received such an order and is legally prevented from disclosing it.
Also known as: Canary Statement
A warrant canary is a creative legal workaround. While companies may be legally prohibited from saying they received a secret government order, they can state that they haven't—until they have.
How It Works
- A company publishes a statement: "We have never received a National Security Letter or secret court order"
- This statement is regularly updated (daily, weekly, or monthly)
- If the statement disappears or stops being updated, users can infer that a secret order may have been received
- The company hasn't technically disclosed anything—they simply stopped saying something
The Legal Basis
In the US, National Security Letters (NSLs) and FISA court orders often come with gag orders preventing disclosure. However:
- The First Amendment may protect the right to not speak
- Companies can't be compelled to lie
- Removing a truthful statement isn't the same as making a false one
Limitations
- Legal uncertainty: No court has definitively ruled on warrant canaries
- Ambiguity: A missing update could mean many things
- Timing: Changes may not be noticed immediately
- Scope: Doesn't indicate what data was requested
What to Look For
Good warrant canaries:
- Are dated and regularly updated
- Are specific about what types of orders haven't been received
- Are signed with a PGP key for authenticity
- Have a clear history of updates
Examples in the Wild
Many privacy-focused companies maintain warrant canaries, including VPN providers, encrypted email services, and secure messaging apps. Check your service provider's transparency page.
Related Terms
Gag Order
A legal order that prevents a company from disclosing that it has received a government request for user data, often accompanying National Security Letters.
National Security Letter
An administrative subpoena issued by U.S. federal agencies (primarily the FBI) for national security investigations. NSLs come with gag orders preventing recipients from disclosing their existence, making them controversial tools of surveillance.
Related Tools
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