You can now read 10 articles in a month for free on BostonGlobe.com. Read as much as you want anywhere and anytime for just 99¢.

The Boston Globe

Nation

Surveillance thwarted terror acts, NSA chief says

Stock exchange was target of plot, House panel told

General Keith Alexander did not face many adversaries during the oversight hearing.

J. Scott Applewhite/Associated Press

General Keith Alexander did not face many adversaries during the oversight hearing.

WASHINGTON — General Keith B. Alexander, the head of the National Security Agency, said Tuesday that American surveillance had helped prevent “potential terrorist events over 50 times since 9/11,” including at least 10 “homeland-based threats.” But he said that a vast majority must remain secret to avoid disclosing sources and methods.

“These programs are immensely valuable for protecting our nation and securing the security of our allies,” Alexander said at a rare public oversight hearing by the House Intelligence Committee.

Continue reading below

In addition, the deputy director of the FBI, Sean Joyce, listed two newly disclosed cases that have now been declassified in an effort to respond to the leaking of classified information about surveillance by Edward J. Snowden, a former NSA contractor.

Joyce described a plot to blow up the New York Stock Exchange by a Kansas City man, whom the agency was able to identify because he was in contact with “an extremist” in Yemen who was under surveillance. Joyce also talked about a San Diego man who planned to send financial support to a terrorist group in Somalia, and who was identified because the NSA flagged his phone number as suspicious through its database of all domestic phone call logs, which was brought to light by Snowden’s disclosures.

“As Americans, we value our privacy and our civil liberties,” Alexander said. “As Americans, we also value our security and our safety. In the 12 years since the attacks on Sept. 11, we have lived in relative safety and security as a nation. That security is a direct result of the intelligence community’s quiet efforts to better connect the dots and learn from the mistakes that permitted those attacks to occur in 9/11.”

The nonadversarial tone of the oversight hearing was captured by its title: How Disclosed NSA Programs Protect Americans, and Why Disclosure Aids Our Adversaries. Both the top Republican and the top Democrat on the committee, Representatives Mike Rogers of Michigan and C.A. Dutch Ruppersburger of Maryland, offered a robust defense of the surveillance programs revealed by Snowden and expressed anger over the leaks, and all five witnesses were executive branch officials who supported the surveillance activities.

In an apparent reference to Snowden, for example, Rogers criticized his actions as “selectively leaking incomplete information” that “paints an inaccurate picture and fosters distrust in our government.” He added, “It is at times like these where our enemies within become almost as damaging as our enemies on the outside.”

Receptive audience

Quote Icon

There was no way to independently verify the claims made by the officials during the hearing.

The director of national intelligence, James R. Clapper Jr., testified at a Senate Intelligence Committee hearing in March that the NSA did not collect records on hundreds of millions of Americans.

Since the revelation of the phone log database, he has explained that his testimony was the “least untruthful” statement he could make about a classified program.

The testimony Tuesday focused on two programs: the collection of the content of e-mails and phone calls of noncitizens abroad who were targeted by the agency without individual court orders under Section 702 of the FISA Amendments Act, and the maintenance of a huge database of domestic phone logs that has been compiled under Section 215 of the Patriot Act.

Both programs are used to try to identify any co-conspirators of terrorism suspects. In recent days, intelligence officials and lawmakers have been disclosing details about safeguards built into the systems, including that the phone logs are destroyed after five years and that fewer than 300 terrorism-related numbers were approved for searching in 2012.

The witnesses clarified other details on Tuesday. James M. Cole, the deputy attorney general, said that while the 702 program can capture the contents of e-mails and phone calls when an overseas target communicates with people in the United States, if officials then want to eavesdrop on purely domestic phone calls or e-mails by anyone in the ring of acquaintances of the overseas target, they must get an individualized warrant from a court.

“If they make a call to inside the United States, that can be collected, but it’s only because the target of that call outside the United States initiated that call and went there,” he said. “If the calls are wholly within the United States, we cannot collect them. If you’re targeting a person who is outside of the United States and you find that they come into the United States, we have to stop the targeting right away.”

In addition, Alexander said that every query to the domestic phone log database was audited by supervisors, and that so far there had been no willful abuses or discipline carried out.

And his deputy, John C. Inglis, said that under court orders, “only 20 analysts at NSA and their two managers, for a total of 22 people, are authorized to approve numbers that may be used to query this database.”

In a rare note of skepticism, Representative Adam B. Schiff, a California Democrat, pressed Alexander about why the FBI could not use subpoenas to get the necessary domestic phone logs surrounding a suspicious number without the government’s obtaining logs of everyone’s calls. Alexander said he was open to discussion, but added, “The concern is speed in a crisis.”

Loading comments...

You have reached the limit of 10 free articles in a month

Stay informed with unlimited access to Boston’s trusted news source.

  • High-quality journalism from the region’s largest newsroom
  • Convenient access across all of your devices
  • Today’s Headlines daily newsletter
  • Subscriber-only access to exclusive offers, events, contests, eBooks, and more
  • Less than 25¢ a week