Is the FBI attempting to get a glance at information Pinterest holds on its users?
It is hard to be certain, but some data recently noted by Electronic Frontier Foundation makes it seem distinctly possible since Pinterest has removed its "warrant canary" from its terms and conditions.
That indicates that Pinterest might well have been served with a National Security Letter by the FBI.
A "warrant canary" refers to an item in a service provider (like Pinterest's) transparency report that says how many subpoenas or warrants it has been issued with for information it holds on users. Warrant canaries are generally in reference to a National Security Letter, which is a subpoena for information that can be issued directly without an order from a judge, because the information at issue is directly connected in some way to national security.
Those letters, for obvious reasons, also carry non-disclosure orders with them, so they can not be directly reported — with one exception. The recipient of the warrant is allowed to report the number of these letters it receives in batches of 250 every six months. The warrant canary is where the letters are reported.
Back to Pinterest. In every quarter since 2013, its transparency report has contained a warrant canary that read "National security: 0."
In its 2015 report, however, this now reads "0-249," indicating the company has potentially received at least one National Security Letter from the FBI in that time.
Digital rights campaign group the Electronic Frontier Foundation, which has been championing "Canary Watch" noted that the change "is certainly the strong implication that Pinterest did receive a national security request, because it would have otherwise have continued to report 0."
However, they also noted:
"In our time working with Canary Watch we have seen many canaries go away and come back, fail to be updated, or disappear altogether along with the website that was hosting it."
"Until the gag orders accompanying national security requests are struck down as unconstitutional, there is no way to know for certain whether a canary change is a true indicator. Instead, the reader is forced to rely on speculation and circumstantial evidence to decide what the meaning of a missing or changed canary is."