April 29 - May 5, 2012 (107 images)

Demonstrators march through the streets on May 1, 2012 in Chicago. Marchers voiced their support for workers' rights and immigration reform and spoke out against corporate greed and Wall Street as part of International Workers Day, a commemoration of the 1886 Haymarket Riot in Chicago. UPI/Brian Kersey

Occupy Wall Street protesters fill Union Square on May Day In New York City on May 1, 2012. Multiple protests are planned throughout the day on the eve of the one year anniversary of Osama Bin Laden's death. UPI/John Angelillo

An Occupy Wall Street walks with a painted face on May Day in Union Square In New York City on May 1, 2012. Multiple protests are planned throughout the day on the eve of the one year anniversary of Osama Bin Laden's death. UPI/John Angelillo

Police make an arrest and throw tear gas to move the crowd back during a May Day protest in Oakland, California on May 1, 2012. UPI/Terry Schmitt