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

itoggle caption Aaron Harris /Reuters/Landov

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

itoggle caption Jim Watson/AFP/Getty Images

President Eisenhower during his farewell address to the nation on Jan. 17, 1961. /AP hide caption

itoggle caption /AP

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

itoggle caption Gregorio Borgia /AP

The National Security Agency headquarters building in Fort Meade, Md. Reuters/Landov hide caption

itoggle caption Reuters/Landov

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

itoggle caption Ivan Sekretarev/AP

Edward Snowden, seen during a video interview with The Guardian. Glenn Greenwald/Laura Poitras /EPA/LANDOV hide caption

itoggle caption Glenn Greenwald/Laura Poitras /EPA/LANDOV

The National Security Agency building at Fort Meade, Md. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP