tl;dr This is a bad legal ruling for privacy and due process in the United States. The US Ninth Circuit Appeals Court in San Francisco issued a ruling declaring that gag orders on the FBI's NSLs (National Security Letters) are completely legal. Reuters article https://www.reuters.com/article/us-usa-surveillance-idUSKBN1A21XJ Link to full text of ruling http://cdn.ca9.uscourts.gov/datastore/opinions/2017/07/17/16-16067.pdf