WASHINGTON -- Ordinary Internet users, American and non-American alike, far outnumber legally targeted foreigners in the communications intercepted by the National Security Agency from U.S. digital networks, according to a four-month investigation by The Washington Post.
Nine of 10 account holders found in a large cache of intercepted conversations, which former NSA contractor Edward Snowden provided in full to The Washington Post, were not the intended surveillance targets but were caught in a net the agency had cast for somebody else.
Many of them were Americans. Nearly half of the surveillance files, a strikingly high proportion, contained names, email addresses or other details that the NSA marked as belonging to U.S. citizens or residents. NSA analysts masked, or "minimized," more than 65,000 such references to protect Americans' privacy, but The Washington Post found nearly 900 additional email addresses, unmasked in the files, that could be strongly linked to U.S. citizens or U.S.residents.
The surveillance files highlight a policy dilemma that has been aired only abstractly in public. There are discoveries of considerable intelligence value in the intercepted messages -- and collateral harm to privacy on a scale that the Obama administration has not been willing to address.
Among the most valuable contents -- which The Washington Post will not describe in detail, to avoid harm to ongoing operations -- are fresh revelations about a secret overseas nuclear project, double-dealing by an ostensible ally, a military calamity that befell an unfriendly power, and the identities of aggressive intruders into U.S. computer networks.
Many other files, described as useless by the analysts but nonetheless retained, have a startlingly intimate, even voyeuristic quality. They tell stories of love and heartbreak, illicit sexual liaisons, mental-health crises, political and religious conversions, financial anxieties and disappointed hopes. The daily lives of more than 10,000 account holders who were not targeted are catalogued and recorded nevertheless.
In order to allow time for analysis and outside reporting, neither Mr. Snowden nor The Washington Post has disclosed until now that he obtained and shared the content of intercepted communications. The cache Mr. Snowden provided came from domestic NSA operations under the broad authority granted by Congress in 2008 with amendments to the Foreign Intelligence Surveillance Act. FISA content is generally stored in closely controlled data repositories, and for more than a year, senior government officials have depicted it as beyond Mr. Snowden's reach.
The Washington Post reviewed roughly 160,000 intercepted email and instant-message conversations, some of them hundreds of pages long, and 7,900 documents taken from more than 11,000 online accounts.
The material spans President Barack Obama's first term, from 2009 to 2012, a period of exponential growth for the NSA's domestic collection.
Taken together, the files offer an unprecedented vantage point on the changes wrought by Section 702 of the FISA amendments, which enabled the NSA to make freer use of methods that for 30 years had required probable cause and a warrant from a judge. One program, code named PRISM, extracts content stored in user accounts at Yahoo, Microsoft, Facebook, Google and five other leading Internet companies. Another, known inside the NSA as Upstream, intercepts data on the move as it crosses the U.S. junctions of global voice and data networks.
No government oversight body, including the Justice Department, the Foreign Intelligence Surveillance Court, intelligence committees in Congress or the president's Privacy and Civil Liberties Oversight Board, has delved into a comparably large sample of what the NSA actually collects -- not only from its targets but from people who may cross a target's path.
Among the latter are medical records sent from one family member to another, resumes from job hunters and academic transcripts of schoolchildren. In one photo, a young girl in religious dress beams at a camera outside a mosque.
Scores of pictures show infants and toddlers in bathtubs, on swings, sprawled on their backs and kissed by their mothers. In some photos, men show off their physiques. In others, women model lingerie, leaning suggestively into a webcam or striking risque poses in shorts and bikini tops.
"None of the hits that were received were relevant," two Navy cryptologic technicians write in one of many summaries of nonproductive surveillance. "No additional information," writes a civilian analyst. Another makes fun of a suspected kidnapper, newly arrived in Syria before the current civil war, who begs for employment as a janitor and makes wide-eyed observations about the state of undress displayed by women on local beaches.
By law, the NSA may "target" only foreign nationals located overseas unless it obtains a warrant based on probable cause from a special surveillance court. For collection under PRISM and Upstream rules, analysts must state a reasonable belief that the target has information of value about a foreign government, a terrorist organization or the spread of nonconventional weapons.
Most of the people caught up in those programs are not the targets and would not lawfully qualify as such. "Incidental collection" of third-party communications is inevitable in many forms of surveillance, but in other contexts the U.S. government works harder to limit and discard irrelevant data. In criminal wiretaps, for example, the FBI is supposed to stop listening to a call if a suspect's wife or child is using the phone.
There are many ways to be swept up incidentally in surveillance aimed at a valid foreign target. Some of those in the Snowden archive were monitored because they interacted directly with a target, but others had more-tenuous links.
If a target entered an online chat room, the NSA collected the words and identities of every person who posted there, regardless of subject, as well as every person who simply "lurked," reading passively what other people wrote.
"1 target, 38 others on there," one analyst wrote. She collected data on them all.
In other cases, the NSA designated as its target the Internet protocol, or IP, address of a computer server used by hundreds of people.
The NSA treats all content intercepted incidentally from third parties as permissible to retain, store, search and distribute to its government customers. Raj De, the agency's general counsel, has testified that the NSA does not generally attempt to remove irrelevant personal content, because it is difficult for one analyst to know what might become relevant to another.
The Obama administration declines to discuss the scale of incidental collection. The NSA, backed by Director of National Intelligence James Clapper Jr., has asserted that it is unable to make any estimate, even in classified form, of the number of Americans swept in. It is not obvious why the NSA could not offer at least a partial count, given that its analysts routinely pick out "U.S. persons" and mask their identities, in most cases, before distributing intelligence reports.
If Mr. Snowden's sample is representative, the population under scrutiny in the PRISM and Upstream programs is far larger than the government has suggested. In a June 26 "transparency report," the Office of the Director of National Intelligence disclosed that 89,138 people were targets of last year's collection under FISA Section 702. At the 9-to-1 ratio of incidental collection in Mr. Snowden's sample, the office's figure would correspond to nearly 900,000 accounts, targeted or not, under surveillance.
U.S. intelligence officials declined to confirm or deny in general terms the authenticity of the intercepted content provided by Snowden, but they made off-the-record requests to withhold specific details that they said would alert the targets of ongoing surveillance. Some officials described Mr. Snowden's handling of the sensitive files as reckless.