Before the first day of each quarter, Purism, following the general rules of warrant canaries, will update its own Warrant Canary page if none of the listed items occurs.
What this is designed to do is to inform users that Purism has not been served with a secret government subpoena. If the warrant canary has not been updated in the time period specified by Purism, users are to assume that Purism has indeed been served with a secret subpoena. The intention is to allow Purism to warn users of the existence of a subpoena passively, without disclosing to others that the government has sought or obtained access to information or records under a secret subpoena. Warrant canaries have been found to be legal by the United States Justice Department, so long as they are passive in their notifications.