Chicago police officers sit in a bus outside the Boeing headquarters in Chicago, Monday, May 21, 2012, awaiting activists with the Occupy Chicago movement who plan to protest against the company's role in building airplanes for the U.S. military. On the second and last day of the international meeting, commuters heading into the city?s Loop business district endured extra security measures and changes to train and bus routes. Many downtown offices told employees to stay home because of the risk of traffic snarls and more protests after a weekend of demonstrations. (AP Photo/Robert Ray)