The term “warrant canary” refers to a practice in which people, companies, or agencies assert something did or did not happen. This is done in plain view so that observers can assume the situation has not changed as long as the assertion continues. If the statement subsequently disappears, the conclusion is that the situation has changed and the canary has died.
The canary reference comes from coal mining. Before modern carbon monoxide detectors were available to alert miners of the deadly gas, caged canaries were placed throughout active mines. The birds are much more susceptible to carbon monoxide poisoning than humans, so if a canary died or even got woozy, that signaled dangerous gas in the atmosphere. Canaries in coals mines acted as a sentinel species and as employed by online companies, a warranty canary implies that a missing warrant is a sentinel.
Reddit’s 2014 Transparency Report stated that the company had “never received a National Security Letter, an order under the Foreign Intelligence Surveillance Act, or any other classified request for user information.” The company also said it would attempt to let the public know if it did receive such requests or orders. However, there is a problem with public disclosure; classified information requests generally include legally enforceable restrictions of public notification about the requests. The restrictions put any company that wants to let people know it has been asked for private information in a tough place if they want to be transparent without breaking the law. Thus the warrant canary.
Reddit’s 2014 and 2015 Transparency Reports both include statistics on many types of requests for information, information removal, and account takedowns, includng the number and types of requests and the percentage of time they complied. What’s missing from the 2015 report is the Reddit’s explicit statement from the previous year that it had no classified requests. The canary fulfilled its duty and died.
