U.S. Department of Homeland Security (DHS) Secretary Janet Napolitano speaks to the press in Panama City November 29, 2010. Napolitano is in Panama to sign a memorandum of understanding between the U.S.and Panama that will enhance the sharing of information and help secure the international aviation system against terrorism and international crime, according to the U.S. Department of Homeland Security press office. REUTERS/Alberto Lowe (PANAMA - Tags: MILITARY POLITICS HEADSHOT)