在美国首都离巴尔的摩——华盛顿公园大道几百米处的一片绿林中,坐落着一幢塔式办公大楼,楼的周围布满接收卫星讯号的银白色抛物面天线。楼内,大批特工人员通过接收卫星讯号、破译密码、翻译和分析形形色色的电子信号,为美国政府和五角大楼提供有关外国政治、军事、经济和重要社会活动等方面的情报。这就是全球最大、耗资最多的情报机构——美国国家安全局的所 Amid the greenery a few hundred meters from the Baltimore - Washington Park Avenue in the U.S. capital lies a towering office tower surrounded by silver-white parabolic antennas that receive satellite signals. In the building, a large number of agents seized intelligence information on foreign politics, military affairs, economy and important social activities for the U.S. government and the Pentagon by receiving satellite signals, deciphering passwords, translating and analyzing various electronic signals. This is where the National Security Agency, the largest and most expensive intelligence agency in the world, is