Civil libertarians saw their hopes for curtailing the National Security Agency's massive digital surveillance program dimmed in the wake of a report from a US government privacy board vindicating much of the international communications dragnet.



The Privacy and Civil Liberties Oversight Board (PCLOB) voted Wednesday to adopt a 200-page report on the NSA's so-called "702" powers, which include the widespread collection of foreign email, voice and text messages and Americans' international calls.



While PCLOB chairman David Medine said those efforts walked "right up to the line of constitutionality," the report largely vindicated the controversial surveillance, the scope of which was disclosed through reporting on documents provided by Edward Snowden, as both effective and legal.



Elisebeth Collins Cook, one of five board members and a Justice Department official in the Bush administration, hailed the digital surveillance as "legal, valuable and subject to intense oversight," and characterized the PCLOB's recommendations as "relatively slight changes at the margins of the program."



In ways both bold and subtle, the long-awaited report blessed the NSA's large-scale collection of digital data, even as it found elements of it problematic.



The PCLOB denied that the 702 siphoning is bulk collection, even though it annually provides the NSA with "hundreds of millions" of different sorts of communications -- blessing an NSA definition that considers only indiscriminate collection, untethered to surveillance targets, to be bulk.



"It's a big program, but it is a targeted program," Medine said after the sparsely-attended Wednesday hearing, which was held in the basement of a Marriott between Congress and the White House.



Civil libertarians castigated the PCLOB over what they consider a counterintuitive definition.



"They say if we're collecting everything from Egypt that's not bulk, everything from [area code] 202 that's not bulk, everything from gmail.com that's not bulk, and that's just bullshit," said Jennifer Granick of the Stanford Law School's Center for Internet and Society.



Dealing another blow to privacy advocates, the board endorsed the NSA, CIA and FBI's warrantless, so-called "backdoor" searches for information from Americans, just weeks after the House of Representatives voted to ban them. While Medine and another board member, former federal judge Patricia Wald, wanted to add greater legal protections, the board advocated restricting the FBI's warrantless searches and urged NSA and CIA analysts to certify that their queries are "reasonably likely to return foreign intelligence information."



"We have seen no evidence of a backdoor, so our recommendations are designed to make sure one is not built," Cook said.



Perhaps most controversially, the PCLOB gave a qualified endorsement to the NSA's practice of siphoning directly from the Internet information that merely references a surveillance target even if the correspondence is neither from nor sent to that target, a practice known as "about" collection.



The PCLOB acknowledged that "about" collection would mean the inevitable collection of purely domestic communications that the NSA is expressly not permitted to acquire, a circumstance intelligence officials called technologically unavoidable after they were compelled to disclose significant overcollection last summer. It urged the NSA to "continually" revisit technological feasibility and the scope of its targeting in order to minimize the intrusion into US privacy. It was far less concerned about non-US privacy considerations.



"About" collection played at most a background role in what now appears to be an epochal 2007-8 debate in Congress to bless what had previously been a surveillance program almost entirely operated by executive prerogative. The PCLOB nevertheless found that the resulting law, the 2008 Fisa Amendments Act, and its critical Section 702 provision, authorized such collection, something Medine said was a "permissible" interpretation by NSA.



All that amounted to a bitter pill for privacy advocates to swallow, particularly coming from a government body that in January had condemned the NSA's bulk surveillance of US phone data.



The PCLOB may have interrupted recent momentum in Congress towards preventing the US government from conducting backdoor searches.



Stanford's Granick held out hope that the PCLOB's assessment would inadvertently bolster the chances for a backdoor-search ban in Congress. The report's perceived moderation could aid legislators in curbing the searches on the argument that they would restore public confidence in US surveillance.



"But for the longer term goal of reining in warrantless, massive collection of communications and for getting countries to protect their communications of all people and not just their own citizens, this doesn't help us at all," Granick said.



The American Library Association similarly declared the PCLOB report a "serious disappointment" and said it should be "an absolute floor for 702 reform and a spur to immediate and broad legislative expansion."



Jameel Jaffer of the ACLU, who testified to the PCLOB in March, called the report "weak."



"It fails to fully grasp the significance of allowing the government to conduct surveillance on this massive scale, of allowing it to store millions of Americans' communications in government databases, and of allowing it to search those databases without any of the safeguards the Constitution has historically been held to require," Jaffer said in a Wednesday statement.



The Center for Constitutional Rights called the PCLOB's treatment of the constitutional implications at stake "disappointingly superficial."



"The board includes no mention whatsoever of free speech, due process, and right to counsel when analyzing the legality of the NSA’s collection of the content of communications between U.S. residents and persons of interest abroad," it said in a statement.



Meanwhile, the leader of the US intelligence community acknowledged his victory.



"In this important report, the PCLOB confirms that Section 702 has shown its value in preventing acts of terrorism at home and abroad, and pursuing other foreign intelligence goals," Director of National Intelligence James Clapper said in a Wednesday statement, adding that he would take the board's privacy concerns "very seriously."



The PCLOB is not done reviewing the NSA's surveillance authorities and their implementation.



When the board next meets, on July 23, it will consider launching a new inquiry into one of the seminal texts behind US intelligence authorities, an executive order known as 12333. The NSA relies upon that obscure document for, among other things, its surreptitious collection of unencrypted information transiting from Google and Yahoo data centers. After the hearing adjourned Wednesday, Medine, Cook and Wald all indicated their appetite for reviewing 12333.