Civil liberties advocates and a bipartisan group in Congress stepped up pressure against the Obama administration’s secret domestic surveillance programs last week via a lawsuit and legislation that could shed light on the scope and legality of the government’s snooping.

The American Civil Liberties Union filed suit in New York federal court against the U.S. Justice Department and other federal agencies, challenging the constitutionality of the government’s review of millions of phone call records of Verizon subscribers. ACLU lawyers contend the government’s "dragnet acquisition" is likely to have a chilling effect on speech.

"The practice is akin to snatching every Amer­ican’s address book — with annotations detailing whom we spoke to, when we talked, for how long, and from where," ACLU deputy legal director Jameel Jaffer said in the complaint, which alleges First Amendment violations. "It gives the government a comprehensive record of our associations and public movements, revealing a wealth of detail about our familial, political, professional, religious, and intimate associations."

On Capitol Hill, eight senators announced legislation to declassify significant opinions by the Foreign Intelligence Surveillance Court, which reviews government surveillance and search applications in national security investigations.

The lawsuit and legislation come after the revelation this month, first reported by The Guardian newspaper, that the National Security Agency was reviewing millions of Verizon records for domestic and international phone calls. A surveillance court order in April is at the heart of the ACLU suit.

Foreign Intelligence Surveillance Act (FISA) court orders and opinions are not ordinarily available for public review, and the court itself sits behind closed doors — no members of the public allowed — inside the E. Barrett Prettyman U.S. Courthouse in downtown Washington. The court has the authority to publicly release its rulings, but disclosure is rare.

Some members of Congress last week expressed concern that the 11-judge court could be interpreting FISA and other authorities, including a provision of the Patriot Act, in ways lawmakers did not intend.

The surveillance court’s opinions contain details of national security operations that should be classified, but the legal interpretations should not remain under wraps, Senator Jeff Merkley (D-Ore.) said in a written statement announcing the bill. He was joined by Senator Mike Lee (R-Utah). The six co-sponsors include Senate Judiciary chairman Patrick Leahy (D-Vt.).

"Americans deserve to know how much information about their private communications the government believes it’s allowed to take under the law," Merkley said. "There is plenty of room to have this debate without compromising our surveillance sources or methods or tipping our hand to our enemies," he continued. "We can’t have a serious debate about how much surveillance of Americans’ communications should be permitted without ending secret law."In late March, U.S. District Judge Reggie Walton, presiding judge of the surveillance court, wrote in a letter to Senate Intelligence Committee chairwoman Diane Feinstein (D-Calif.) that the preparation of public summaries of the secret court’s opinions isn’t an easy task. His letter was first published by the Secrecy News blog of the Federation of American Scientists.

There’s "the very real problem," Wal­ton said, of segregating classified information from legal analysis.

"As members of Congress who have seen the opinions know, most FISC opinions rest heavily on the facts presented in the particular matter before the court," Walton wrote. "Thus, in most cases, the facts and the legal analysis are so inextricably intertwined that excising the classified information from the FISC’s analysis would result in a remnant void of much or any useful meaning."

On June 10, the ACLU asked the court to unseal orders and opinions addressing the meaning and scope of Section 215 of the Patriot Act — the provision under which the Justice Department sought access to Verizon phone call records.

"The government appears to have secretly given itself shockingly broad surveillance powers, thereby depriving the public of the chance to weigh in on the wisdom of an unprecedented invasion of privacy," Alexander Abdo, a staff attorney with the ACLU National Security Project, said in a written statement.

The surveillance court on June 12 handed the advocacy group Electronic Frontier Foundation a rare win in a dispute with the Justice Department over a sealed opinion. Walton said the court’s rules would not block prosecutors from disclosing the opinion if a trial judge determines it can be released under the Freedom of Information Act (FOIA).

The Justice Department had urged the surveillance court to keep the ruling secret. Now, it’s up to U.S. District Judge Amy Berman Jackson whether any of part of the opinion can see the light of day. All that’s publicly known about the ruling is that the surveillance court found — at least in this one instance — government surveillance had run afoul of Fourth Amendment protections. Walton said in his ruling that the surveillance court "expresses no opinion" on whether the opinion is subject to disclosure under FOIA.

"The larger significance of the decision, beyond its impact on the FOIA case in district court, is that the FISC is now on record saying that, to the extent there is secret law governing controversial surveillance activities, that is the creature of the Executive, and not the FISA court," Electronic Frontier Foundation lawyer David Sobel said.

The fight for transparency won’t be limited to the halls of Congress and federal courthouses. Several technology and social-media companies, including Google Inc. and Facebook Inc., asked the Justice Department last week to allow the companies to publish, in greater detail, their compliance with government demands for customer data.

Google’s chief legal officer David Drummond wrote in a letter to Attorney General Eric Holder Jr. and FBI Director Robert Mueller III that "assertions in the press that our compliance with [law enforcement] requests gives the U.S. government unfettered access to our users’ data are simply untrue."

Drummond said that Google, which already publishes some data about government requests, wants to reveal FISA disclosures — both the number of requests the company receives and the scope of the demands.

"Google has nothing to hide," Drummond wrote.

Todd Ruger can be contacted at truger@alm.com and Mike Scarcella at mscarcella@alm.com.