Facebook has published the details of 13 historical national security letters it’s received for user data.

The embattled social media giant said that the letters dated between 2014 and 2017 for several Facebook and Instagram accounts.

These demands for data are effectively subpoenas, issued by the FBI without any judicial oversight, compelling companies to turn over limited amounts of data on an individual who is named in a national security investigation. They’re controversial — not least because they come with a gag order that prevents companies from informing the subject of the letter, let alone disclosing its very existence.

Companies are often told to turn over IP addresses of everyone a person has corresponded with, online purchase information, email records and cell-site location data.

But since the introduction of the Freedom Act, passed in the aftermath of the Edward Snowden revelations, the FBI has to periodically review the gag orders.

Chris Sonderby, Facebook’s deputy general counsel, said that the government lifted the non-disclosure orders on the letters over the course of this year.

“We always scrutinize each government request we receive for account data to make sure it is legally valid,” said Sonderby.

It’s not the first time Facebook has disclosed a national security letter. Its first letter, revealed in 2016, dated back to 2015. (You can read all of the disclosed national security letters here.)

News of the national security letters dropped a day after a highly critical report by The New York Times that revealed some of the company’s shady tactics over the years designed to deflect attention from its various scandals, including attempts to discredit activists and protesters.

Facebook’s latest transparency report shows that the number of government demands for data rocketed by 26 percent year-over-year, from 82,341 to 103,815 requests.

The U.S. government’s demands for customer data went up by 30 percent, to 42,466 total requests, Facebook said, affecting 70,528 accounts. The company said that more than half included a non-disclosure clause that prevented the company from informing the user.

Most of the legal orders were court-authorized search warrants.

For its latest reporting period, Facebook also said that the number of other national security orders more than doubled year-over-year, from between 12,500-12,999 accounts during July-December 2016 to 25,000-25,499 accounts during January-June 2017.

Under current Justice Dept. reporting rules, companies are subject to a six-month reporting delay.