Updated

The Obama administration quietly won permission from a surveillance court in 2011 for the National Security Agency to search deliberately for Americans' communications in its huge databases of intercepted phone calls and emails, according to a published report.

The Washington Post reported Saturday that officials in 2011 got the court to lift the ban on those kinds of searches, which the court imposed in 2008 at the government's request. The court also extended the length of time the NSA is allowed to retain intercepted communications from five to six years.

The search authority has been used, the Post reported, noting that the permission to search and keep data longer expanded the NSA's authority in significant ways without public debate or any specific authority from Congress. The newspaper cited interviews with government officials and documents that include a recently released 2011 opinion by U.S. District Judge John D. Bates, then chief judge of the Foreign Intelligence Surveillance Court.

The court decision allowed the NSA "to query the vast majority" of its communications databases using the email addresses and phone numbers of Americans and legal residents without a warrant, according to Bates' opinion. The queries must be "reasonably likely to yield foreign intelligence information." And the results are subject to the NSA's privacy rules.

The White House on Sunday directed questions on the issue to the Office of the Director of National Intelligence.

The court in 2008 imposed a wholesale ban on such searches at the government's request, said Alex Joel, civil liberties protection officer at ODNI. He told the Post the government included this restriction "to remain consistent with NSA policies and procedures that NSA applied to other authorized collection activities."

But in 2011, "we did ask the court" to lift the ban to more rapidly and effectively identify relevant foreign intelligence communications, ODNI general counsel Robert S. Litt said. "We wanted to be able to do it," he said, referring to the searching of Americans' communications without a warrant.

Joel said the authority would be needed in certain situations, such as when the NSA learns of a rapidly developing terrorist plot and suspects that a U.S. person may be a conspirator. Searching for communications to, from or about that person can help assess that person's involvement and whether he is in touch with terrorists who are surveillance targets, he said.

A pair of Democratic senators, Ron Wyden of Oregon and Mark Udall of Colorado, warned last year the administration had a "back-door search loophole" that enabled the NSA to scour intercepted communications for those of Americans. They introduced legislation to require a warrant, but could not disclose the court's authorization or whether the NSA was already conducting such searches under classification rules.

The searches take place under a surveillance program Congress authorized in 2008 under the Foreign Intelligence Surveillance Act. Under that law, the target must be a foreigner "reasonably believed" to be outside the United States, and the court must approve the targeting procedures in an order good for one year.

But some are concerned that a warrant for each target would no longer be required. That means communications with Americans could be picked up without a court first determining that there is probable cause that the people they were talking to were terrorists, spies or "foreign powers."

Udall told the Post that is why it is important to require a warrant before searching for Americans' data, adding, "Our founders laid out a roadmap where Americans' privacy rights are protected before their communications are seized or searched — not after the fact."