The U.S. government has released a secret court ruling from 2011 that found some surveillance conducted by the National Security Agency illegal and that estimated the NSA collected many thousands of "wholly domestic communications" between Americans.
The Electronic Frontier Foundation heralded as a "victory" Wednesday's release of the 86-page opinion by the Foreign Intelligence Surveillance Court (FISC), set up under the 1978 Foreign Intelligence Surveillance Act.
In a statement following the release of the court opinion, Director for National Intelligence James Clapper announced the establishment of a group that will review the United States' surveillance capabilities and issue a report by mid-December.
The group will assess "whether the U.S. employs its technical collection capabilities in a manner that optimally protects our national security...while appropriately accounting for other policy considerations, such as the risk of unauthorized disclosure and our need to maintain the public trust."
The court document, dated October 3, 2011, found some of the NSA's collections to be in breach of the Fourth Amendment, which protects against unreasonable searches and seizures.
It's not the first time the opinion has been released -- it was published in January, but the document was so heavily redacted it was impossible to read, bar a single sentence that offered nothing of value.
In the readable (albeit still heavily redacted) opinion, the court said it was "troubled" that government revelations had, for the third time in less than three years, uncovered a "substantial misrepresentation" of the scope of NSA data-collection programs involving Internet traffic.
The now-discontinued "upstream" program diverted large quantities of international data from fiber cables running in and out of the U.S. into a data center, where it could be stored and analyzed.
Investigative reporting by ZDNet in June first detailed how fiber and telecommunications companies were ordered under law to allow vast amounts of data belonging to U.S. citizens and foreign nationals to be wiretapped.
Realistically, the NSA was unable to filter out the communications of Americans speaking to other Americans.
According to NSA estimates, as many as 56,000 "wholly domestic communications" may have been acquired, and are being acquired, by the government agency per year.
The NSA acquires more than 250 million Internet communications each year under Section 702 of FISA, the document states. Most are obtained from Internet providers. The court opinion also says the NSA's upstream program constitutes only approximately 9 percent of the total Internet communications being acquired under Section 702.
On Tuesday, a report by The Wall Street Journal claimed the NSA could access as much as 75 percent of all U.S. Internet traffic.
"The exceptions to minimization requirements mean information gathered on Americans could be used in ordinary criminal investigations, according to rules approved" by the FISC, the Journal wrote.
One month after the FISC ruled the upstream program unconstitutional, the NSA adjusted its collection process to filter out wholly American traffic from international traffic. It also purged any domestic traffic that it received.
"Contrary to the government's repeated assurances, [the] NSA had been routinely running [search] queries of the metadata using querying terms that did not meet the required standard for querying," the FISC opinion said.
The court concluded that this requirement had been "so frequently and systematically violated that it can fairly be said that this critical element of the overall [...] regime has never functioned effectively."
In a joint statement (PDF) issued late Wednesday, the NSA and the Office of the Director of National Intelligence said media reports based on the Journal's article "provide an inaccurate and misleading picture of NSA's collection programs."
"Press reports based on an article published in today's Wall Street Journal mischaracterize aspects of NSA's data collection activities conducted under Section 702 of the Foreign Intelligence Surveillance Act," the statement read. "The NSA does not sift through and have unfettered access to 75 percent of the United States' online communications."
Update, 10 p.m. PT: Adds statement from NSA about Wall Street Journal article.
A slightly different version of this story originally appeared as "Secret court 'troubled' by NSA surveillance, ruled illegal" on ZDNet.