Hundreds of protesters, many affiliated with the Occupy Wall Street movement, demonstrate in front of the Boeing headquarters on the second day of the NATO summit on May 21, 2012 in Chicago, Illinois. Sixty heads of state, 2,500 journalists and thousands of protesters have converged on Chicago for the two day NATO meeting which began on Sunday and looks to address the situation in Afghanistan among other global defense issues. Chicago police are preparing for the worst with many officers in riot gear and with their numbers enhanced by police from outside the city. (Photo by Spencer Platt/Getty Images)
Demonstrators launched another round of protests May 21 in the final hours of the NATO summit, marching through an unusually quiet downtown Chicago to the headquarters of Boeing and President Barack Obama's campaign.