6 / 37
A protester wearing mask of Chicago Mayor Rahm Emanuel, shoots out silly string during a demonstration outside Boeing corporate offices Monday, May 21 2012, in Chicago, on the final day of the NATO summit. (AP Photo/Charles Rex Arbogast)

Protesters swarm on final day of NATO summit

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.