He said the surveillance programs were critical to unraveling terrorist plots at home and abroad. In particular, he cited the cases of Najibullah Zazi, an Afghan American who pleaded guilty to planning suicide attacks in New York, and Pakistani American David C. Headley, who was arrested in 2009 for his role in a terrorist attack the year before in Mumbai, and who was plotting to attack a Danish newspaper that published a satirical cartoon of the prophet Muhammad.
“I think what we’re doing to protect American citizens here is the right thing,’’ Alexander said under sometimes hostile questioning before the Senate Appropriations Committee. “Our agency takes great pride in protecting this nation and our civil liberties and privacy.’’
Alexander’s appearance featured the unusual spectacle of the head of the ultra-secretive NSA publicly discussing highly classified programs as the administration is pursuing possible criminal charges against a former NSA contractor who says he leaked the details of those efforts.
Alexander’s words reflected the intense debate consuming Washington since last week’s revelations that the government has been collecting the call records of millions of Americans and scooping up e-mail and other user records of foreign targets from nine leading technology companies, including Google, Facebook and Microsoft.
The confessed leaker, Edward Snowden, 29, surfaced publicly again Wednesday, saying that the United States has mounted massive hacking operations against hundreds of Chinese targets since 2009 as part of a global campaign. Snowden, in an interview in Hong Kong, vowed to fight the U.S. government in the courts if it attempts to extradite and prosecute him.
U.S. officials said criminal charges are being prepared against Snowden, but they declined to specify the nature of the charges or when they might be filed. The officials spoke on the condition of anonymity to discuss ongoing deliberations.
The Obama administration has defended its extensive surveillance, and President Obama has said he welcomes a public debate about the programs. Alexander followed up on that pledge Wednesday, vowing to quickly make public data showing the phone program has prevented attacks.
“Over the next week, it will be our intent to get those figures out. . . . I want the American people to know we’re being transparent here,’’ he said.
The phone-records program, disclosed last week by Britain’s Guardian newspaper, collects customer “metadata,” including the phone numbers dialed and the length of calls — and, senators said, location data, which intelligence analysts use to detect patterns and personal connections. The administration said that the program does not monitor the content of calls and that it has been reviewed by a secret surveillance court and Congress.