The Silence That Speaks

In the US, the government can issue a National Security Letter (NSL) that forces a company to turn over data AND imposes a "gag order" preventing them from telling anyone about it.

This creates a paradox: how can a company warn its users if it's legally forbidden to speak?

The answer is a Warrant Canary. It's a regularly published statement that says: "As of this date, we have NOT received any secret warrants."

When the Canary Dies

If the company receives an NSL, they can't legally say "We received an NSL." But they can simply stop publishing the canary.

The silence allows users to infer that something has happened. It is the only legal way to signal a compromise in a gagged environment.

ZeroLatch publishes a signed warrant canary every 30 days. If you ever see it outdated, assume the worst.