The President Barack Obama administration is informing a federal judge that if it's forced to disclose a secret court opinion about the government illegally spying on Americans, the likely result could be "exceptionally grave and serious damage to the national security."

The statement came in response to a lawsuit demanding the administration disclose a Foreign Intelligence Surveillance Court opinion issued as early as last year. Sen. Ron Wyden (D-Oregon) was briefed on the opinion as a member of the Intelligence Committee and was authorized last year to reveal that the surveillance had "circumvented the spirit of the law" and was "unreasonable under the Fourth Amendment."

The Electronic Frontier Foundation of San Francisco sought the ruling as part of a Freedom of Information Act request. The government rejected the request. The digital rights group sued in U.S. District Court for the District of Columbia.

In response, the government said that disclosure of the secret opinion should be barred because it "implicates classified intelligence sources and methods." (.pdf)

Jacqueline Coleman Snead, a senior Justice Department counsel, added Monday that the EFF "cannot contend otherwise."

Specifically, the EFF wants the government to make public a secret court ruling that found the feds had broken a 2008 wiretapping law, known as the FISA Amendments Act, that had legalized President George W. Bush's warrantless wiretapping program that was implemented immediately after the 2001 terror attacks.

The public learned of the ruling only because of Wyden's authorized statements about it last year.

The FISA Amendments Act allows the government to conduct widespread e-mail and phone surveillance inside the United States, without probable-cause warrants, targeting people or groups "reasonably believed to be located outside the United States to acquire foreign intelligence information." In other words, the government can collect e-mails and phone calls in the United States so long as the target is a suspected terrorist group overseas. If the government collects e-mails that are sent by people believed to be American, the person's identity is supposed to be given a pseudonym or "minimized."

The government is required to get approval from a secret court known as the Foreign Intelligence Surveillance Court to conduct such surveillance. It's opinions are secret, and the government wants to keep them that way.

That's because the FISA Amendments Act generally requires the Foreign Intelligence Surveillance Court to rubber-stamp terror-related electronic surveillance requests. The government does not have to identify the target or facility to be monitored. It can begin surveillance a week before making the request, and the surveillance can continue during the appeals process if, in a rare case, the secret court rejects the surveillance application.

Hat Tip: Mike Scarcella