Glenn Greenwald, left, and David Miranda after Miranda's arrival at Rio de Janeiro's International Airport on Aug. 19, 2013. Miranda had been detained for nine hours at London's Heathrow Airport. Authorities questioned him about Greenwald's reporting of the "NSA leaks." Ricardo Moraes /Reuters/Landov hide caption

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Sen. Rand Paul, R-Ky., in front of the federal district court in Washington, where he filed his lawsuit against the Obama administration and the NSA. Charles Dharapak/AP hide caption

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Travelers at Pearson International Airport in Toronto earlier this month. At an unnamed airport, Canada's spy agency tested a program that allowed them to track those who took advantage of free Wi-Fi. Aaron Harris /Reuters/Landov hide caption

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President Obama speaks about the National Security Agency and intelligence agencies surveillance techniques during a speech Friday at the Department of Justice in Washington, D.C. Jim Watson/AFP/Getty Images hide caption

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LISTEN: President Obama's national security address
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On 'Morning Edition': NPR's Mara Liasson reports on the politics of the NSA debate
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President Eisenhower during his farewell address to the nation on Jan. 17, 1961. /AP hide caption

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The NSA can reportedly monitor what's going on with 100,000 computers around the world. Gregorio Borgia /AP hide caption

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From 'Morning Edition': NPR's Carrie Johnson on the hearing about the NSA's surveillance programs
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The National Security Agency headquarters building in Fort Meade, Md. Reuters/Landov hide caption

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NSA Says It Would Welcome Public Advocate At FISA Court
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President Obama walks with German Chancellor Angela Merkel in St. Petersburg, Russia, on Sept. 6, 2013. Relations between the two allies are strained after documents leaked by Edward Snowden, a former National Security Agency contractor, suggested the agency had spied on Merkel and other world leaders. Ivan Sekretarev/AP hide caption

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