Gen. William K. Harrison, Jr., seated at left, and North Korean Gen. Nam Il, seated at right, sign armistice documents in Armistice Hall in Panmunjom, a no man's land between the Koreas, on July 26, 1953. AP hide caption

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Employee Sean Tippett works in an operations room at the headquarters of Cisco Systems, a leading provider of Internet network technology, in San Jose, Calif. Experts are debating the need for Internet traceability for security purposes -- and what that would mean for online anonymity and civil liberties in places such as China and Iran. Paul Sakuma/AP hide caption

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Defense Secretary Robert Gates delivers the oath of office to Gen. Keith Alexander (right) during the activation ceremony of U.S. Cyber Command at Fort Meade, Md., last month. Cherie Cullen/AP/Department of Defense hide caption

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A North Korean soldier (left) and a South Korean soldier stand opposite each other at the demilitarized zone separating the two Koreas. Yonhap/AFP/Getty Images hide caption

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Director of National Intelligence Dennis Blair, seen here in February, offered his resignation Thursday. During the 16 months on the job, Blair struggled to establish his authority over the CIA and other U.S. intelligence agencies. Manuel Balce Ceneta/AP hide caption

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Iranian President Mahmoud Ahmadinejad addresses the Nuclear Nonproliferation Treaty conference Monday at United Nations headquarters. Richard Drew/AP hide caption

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