An agent patrols the day before the NATO Summit begins in Chicago

 
An agent patrols the day before the NATO Summit begins in Chicago
A U.S. Secret Service agent patrols behind a security fence that marks the "Red Zone" area surrounding McCormick Place, the site of the NATO Summit, in Chicago May 19, 2012. The Summit runs May 20-21. REUTERS/Frank Polich (UNITED STATES - Tags: POLITICS)