Microsoft published its biannual transparency report on Thursday, revealing its first National Security Letter from the FBI.
The FBI uses NSLs, often accompanied by temporary gag orders on revealing them, to acquire information on technology companies’ users.
Other companies like Facebook, Google and Twitter have made NSLs they received from the FBI public in recent transparency reports.
In addition to the letter, Microsoft also noted in its report that the number of U.S. foreign intelligence surveillance requests it received remained consistent from the second half of 2015 to the first half of 2016.
The Washington-based technology company said that it received between 0 and 499 Foreign Intelligence Surveillance Act (FISA) requests in both the first and second halves of 2015, as well as from January to June 2016.
FISA requests, which unlike NSLs require judicial approval, are used by the government to collect foreign intelligence and monitor foreign agents and individuals suspected of engaging in espionage.
Despite the requests, the company noted in the same timespan that the overall amount of users affected by the requests had decreased, from between 17,500 and 17,999 to between 12,000 and 12,499.
In a blog post released with the report, Microsoft criticized excessive security and surveillance orders and praised the USA Freedom Act that passed in 2015, which allows tech companies to disclose NSLs to the public after temporary gag orders.
“There are times when secrecy is vital to an investigation, but too often secrecy orders are unnecessarily used, or are needlessly indefinite and prevent us from telling customers of intrusions even after investigations are long over,” wrote Steve Lippman, Microsoft’s director of corporate responsibility.
“That’s why we asked a federal court to weigh in on the increasing frequency of these orders. Our hope is this lawsuit will lead to new rules or laws that keep secrecy for times when it is truly essential.”
Microsoft has filed several lawsuits against the government related to customer privacy and transparency.