A TSA worker searches a bag at Oakland International Airport. Justin Sullivan/Getty Images hide caption

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A Yemeni soldier operates at the checkpoint on the northern entrance of the capital, San'a, on Jan. 13. Nasser Nasser/AP hide caption

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FBI Director Robert Mueller testifies Wednesday on Capitol Hill on the bureau's counterterrorism efforts. During the hearing, Senate Judiciary Committee Chairman Patrick Leahy confronted Mueller on a report that was released by the Justice Department's Office of the Inspector General saying the FBI illegally obtained thousands of Americans' telephone records during the Bush administration. Mandel Ngan/AFP/Getty Images hide caption

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Homeland Security Secretary Janet Napolitano (L) testifies during a Senate Commerce, Science and Transportation Hearing. Ann Heisenfelt/Getty Images hide caption

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Umar Farouk Abdulmutallab, here in Milan, Mich., was charged in federal court Dec. 28, 2009, with trying to detonate an explosive device on a Dec. 25 flight from Amsterdam to Detroit. U.S. Marshals Service/AP hide caption

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