Warrant Canaries: How Services Signal Government Interference

A warrant canary is a regularly updated statement declaring that a service has NOT received any secret government subpoenas or gag orders. When the statement stops being updated, it signals potential compromise.

How It Works Legally

In many jurisdictions, a National Security Letter (NSL) or FISA order prohibits the recipient from disclosing they received it. However, the law doesn't (arguably) compel someone to actively lie. So by stopping the canary update, the service passively signals interference without technically violating the gag order.

What to Watch For

PGP-signed canary statements should be updated at a stated interval (weekly, monthly). Check: is the canary still being updated on schedule? Is the PGP signature valid? Has the language changed subtly? Missing updates, changed wording, or invalid signatures are all warning signs.

Limitations

Warrant canaries have never been tested in court — their legal standing is uncertain. A service could stop updating for non-legal reasons (admin gone, forgot, server issues). Some argue that courts could compel continuing a canary. Despite limitations, canaries remain a useful signal in the absence of alternatives.