NSA Capitol Hill 18June2013
(From left) Deputy U.S. Attorney General James Cole, NSA Deputy Director John Inglis, NSA Director U.S. Army General Keith Alexander, FBI Deputy Director Sean Joyce and Office of the Director of National Intelligence General Counsel Robert Litt testify before a U.S. House Permanent Select Committee on Intelligence hearing on recently disclosed NSA surveillance programs, at the U.S. Capitol in Washington June 18, 2013. Reuters

Since the terrorist attacks of Sept. 11, 2001, the government’s surveillance programs have helped thwart a terrorist attack in more than 50 instances, according to Gen. Keith Alexander, director of the National Security Agency. The intelligence community has decided to disclose four of these cases.

Speaking at a House Intelligence Committee hearing on Tuesday, top intelligence community officials including Gen. Alexander defended the NSA’s surveillance of phone records and Internet communications, which has come under fire as a breach of Americans’ civil liberties since the program was revealed by former NSA contractor Edward Snowden. The five witnesses repeatedly told the committee that robust protections were in place to protect citizens’ privacy.

The leaks of classified documents revealed the existence of two surveillance programs, which the government operates under the authority of Section 215 of the USA Patriot Act and Section 702 of the FISA Amendments Act. The former green-lights the collection of Americans’ phone records and the latter authorizes foreign surveillance.

To prove the necessity of these programs, Sean Joyce, deputy director of the Federal Bureau of Investigation, described four of the instances in which, under the authority of either Section 215 or Section 702, an attack was thwarted. Two of the cases were previously undisclosed, according to the Guardian newspaper. The examples show a process whereby the NSA's programs detected a suspicious individual within the U.S., and the FBI then moved to identify and investigate that person.

The first example was the case of Najibullah Zazi, who confessed to plotting to bomb the New York City subway system in 2009. Joyce confirmed that the NSA’s Internet surveillance program led officials to a suspect in Colorado who turned out to be Zazi. The FBI took the necessary legal steps to identify him and ultimately capture him, in concert with authorities in New York. Under Section 215's authority, Joyce said, the NSA was also able to nail down a “previously unknown [phone] number of one of the co-conspirators.”

“Without the 702 tool, we would not have identified Najibullah Zazi,” Joyce said later in the hearing.

The second instance described was a thwarted plot to bomb the New York Stock Exchange. Under Section 702's authority, the NSA monitored a known extremist in Yemen who was communicating with a man in Kansas City, Mo. This information led the FBI to Khalid Ouazzani, his co-conspirators and ultimately the plot to bomb the NYSE. Ouazzani ultimately confessed to sending money to al-Qaeda and was never convicted for the stock exchange plot.

The third instance cited by Joyce was the case of David Headley, an American in Chicago who aided the 2008 Mumbai terrorist attacks. The FBI had received a tip about his involvement in the attacks when the NSA’s 702 surveillance also identified Headley as involved in a plot to bomb a Danish newspaper office that had published cartoons of the Prophet Mohamed that were considered offensive by some Muslims. “Headley later confessed to personally conducting surveillance of the Danish newspaper office,” Joyce said.

Regarding the final case, Joyce testified that data collection under Section 215 helped uncover terrorist activity that the FBI had been unable to detect previously. In 2007, the FBI closed an investigation it had launched shortly after Sept. 11, when it could not connect the subject of the investigation to terrorist activity. Years later, under its Section 215-sanctioned metadata collection program, the NSA identified a phone number in San Diego that was in contact with a known terrorist overseas. The NSA’s discovery allowed the FBI to reopen the investigation and disrupt the terrorist activity. Joyce later confirmed that the activity involved providing financial support to a designated terrorist group overseas.

In addition to those four cases, Alexander said the intelligence community is collecting information on “over 50 cases that are classified and will remain classified,” in which the surveillance programs helped thwart an attack. Alexander said that information would be shared with the House and Senate intelligence committees.

“The foreign intelligence programs that we are talking about are the best counterterrorism tools that we have to go after these guys,” Alexander said after Joyce recalled the four examples. “We can’t lose those capabilities.”

Rep. Mike Rogers, chairman of the House Intelligence Committee and a vocal defender of these programs, echoed these sentiments in his opening remarks on Tuesday. Without these programs, he said in prepared remarks, “I fear we will return to the position we were in prior to the attacks of September 11, 2001. And that should be unacceptable to all of us.”

Gen. Keith Alexander and Sean Joyce testifying: