Intelligence officials refer to Edward J. Snowden’s job as a National Security Agency contractor as “systems administrator” — a bland name for the specialists who keep the computers humming. But his last job before leaking classified documents about N.S.A. surveillance, he told the news organization The Guardian, was actually “infrastructure analyst.”
It is a title that officials have carefully avoided mentioning, perhaps for fear of inviting questions about the agency’s aggressive tactics: an infrastructure analyst at the N.S.A., like a burglar casing an apartment building, looks for new ways to break into Internet and telephone traffic around the world.
That assignment helps explain how Mr. Snowden got hold of documents laying bare the top-secret capabilities of the nation’s largest intelligence agency, setting off a far-reaching political and diplomatic crisis for the Obama administration.
Even as some members of Congress have challenged the N.S.A.’s collection of logs of nearly every phone call Americans make, European officials furiously protested on Sunday after Mr. Snowden’s disclosure that the N.S.A. has bugged European Union offices in Washington and Brussels and, with its British counterpart, has tapped the Continent’s major fiber-optic communications cables.
On Sunday evening, The Guardian posted an article saying documents leaked by Mr. Snowden show 38 embassies and missions on a list of United States electronic surveillance targets. Some of those offices belong to allies like France, Italy, Japan and Mexico, The Guardian said.
Mr. Snowden, who planned his leaks for at least a year, has said he took the infrastructure analyst position with Booz Allen Hamilton in Hawaii in March, evidently taking a pay cut, to gain access to a fresh supply of documents.
“My position with Booz Allen Hamilton granted me access to lists of machines all over the world the N.S.A. hacked,” he told The South China Morning Post before leaving Hong Kong a week ago for Moscow, where he has been in limbo in the transit area of Sheremetyevo airport. “That is why I accepted that position about three months ago.”
A close reading of Mr. Snowden’s documents shows the extent to which the eavesdropping agency now has two new roles: It is a data cruncher, with an appetite to sweep up, and hold for years, a staggering variety of information. And it is an intelligence force armed with cyberweapons, assigned not just to monitor foreign computers but also, if necessary, to attack.
After the 2001 terrorist attacks, the documents suggest, the N.S.A. decided it was too risky to wait for leads on specific suspects before going after relevant phone and Internet records. So it followed the example of the hoarder who justifies stacks of paper because someday, somehow, a single page could prove vitally important.
The agency began amassing databases of “metadata” — logs of all telephone calls collected from the major carriers and similar data on e-mail traffic. The e-mail program was halted in 2011, though it appears possible that the same data is now gathered in some other way.
The documents show that America’s phone and Internet companies grew leery of N.S.A. demands as the years passed after 9/11, fearing that customers might be angry to find out their records were shared with the government. More and more, the companies’ lawyers insisted on legal orders to compel them to comply.
So the N.S.A. came up with a solution: store the data itself. That is evidently what gave birth to a vast data storage center that the N.S.A. is building in Utah, exploiting the declining cost of storage and the advance of sophisticated search software.
Those huge databases were once called “bit buckets” in the industry — collections of electronic bits waiting to be sifted. “They park stuff in storage in the hopes that they will eventually have time to get to it,” said James Lewis, a cyberexpert at the Center for Strategic and International Studies, “or that they’ll find something that they need to go back and look for in the masses of data.” But, he added, “most of it sits and is never looked at by anyone.”
Indeed, an obscure passage in one of the Snowden documents — rules for collecting Internet data that the Obama administration wrote in secret in 2009 and that the Foreign Intelligence Surveillance Court approved — suggested that the government was concerned about its ability to process all the data it was collecting. So it got the court to approve an exception allowing the government to hold on to that information if it could not keep up. The rules said that “the communications that may be retained” for up to five years “include electronic communications acquired because of the limitation on the N.S.A.’s ability to filter communications.”
As one private expert who sometimes advises the N.S.A. on this technology put it: “This means that if you can’t desalinate all the seawater at once, you get to hold on to the ocean until you figure it out.”
Collecting that ocean requires the brazen efforts of tens of thousands of technicians like Mr. Snowden. On Thursday, President Obama played down Mr. Snowden’s importance, perhaps concerned that the manhunt was itself damaging the image and diplomatic relations of the United States. “No, I’m not going to be scrambling jets to get a 29-year-old hacker,” the president said during a stop in Senegal.
Mr. Obama presumably meant the term to be dismissive, suggesting that Mr. Snowden (who turned 30 on June 21) was a young computer delinquent. But as an N.S.A. infrastructure analyst, Mr. Snowden was, in a sense, part of the United States’ biggest and most skilled team of hackers.
The N.S.A., Mr. Snowden’s documents show, has worked with its British counterpart, Government Communications Headquarters, to tap into hundreds of fiber-optic cables that cross the Atlantic or go on into Europe, with the N.S.A. helping sort the data. The disclosure revived old concerns that the British might be helping the N.S.A. evade American privacy protections, an accusation that American officials flatly deny.
And a secret presidential directive on cyberactivities unveiled by Mr. Snowden — discussing the primary new task of the N.S.A. and its military counterpart, Cyber Command — makes clear that when the agency’s technicians probe for vulnerabilities to collect intelligence, they also study foreign communications and computer systems to identify potential targets for a future cyberwar.