A police lieutenant swings his baton at an Occupy Wall Street activist on May 1, 2012 in New York. Hundreds of activists with a variety of causes spread out over New York City Tuesday on International Workers Day, or May Day, with Occupy Wall Street members leading a charge against financial institutions. (AP Photo/Mary Altaffer) 

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People take part in a march as part of the annual May Day workers' events on May 1, 2012 in Paris.(Guillaume Baptiste/AFP/GettyImages) # 

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Demonstrators march down Broadway during a May Day protest on May 1, 2012 in New York City. Occupy Wall Street demonstrators joined labor groups in a march to protest economic injustice and observe International Labor Day. (John Moore/Getty Images) # 

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A trade union activist dances during a rally organized by various trade unions affiliated to the Unified Communist Party of Nepal (Maoist) to mark May Day in Katmandu, Nepal, on May 1, 2012. (AP Photo/Binod Joshi) # 

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Riot police use tear gas against demonstrators during a May Day rally in central Ankara, Turkey, on May 1, 2012.(Reuters/Umit Bektas) # 

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Portland police move in to make arrests during a May Day march and protest in Portland, Oregon, on May 1, 2012.(AP Photo/Don Ryan) # 

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Activists, maids and workers rally during a May Day protest in Hong Kong on May 1, 2012. About 5,000 workers, domestic helpers and activists held a noisy procession and marched through the city center to call for better working conditions and a raise of the minimum wage which was implemented in 2011. (Laurent Fievet/AFP/GettyImages) # 

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Occupy Wall Street activists, one wearing a Guy Fawkes mask, rest on a sidewalk during a May Day demonstration in New York, on May 1, 2012. (Reuters/Allison Joyce) # 

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An Occupy Wall Street activist yells at police who are guarding other policemen making an arrest in downtown Manhattan, New York, on May 1, 2012. (Reuters/Adrees Latif) # 

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Protestors sit with red flags during a May Day rally in central Istanbul, on May 1, 2012. Tens of thousands of workers gathered at Taksim square in the heart of Turkey's biggest city Istanbul to celebrate May Day. (Bulent Kilic/AFP/Getty Images) # 

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A demonstrator clashes with riot policemen during May Day rallies in Santiago, Chile, on May 1, 2012. (Reuters/Carlos Vera) # 

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An Oakland police officer pauses after being hit in the face with paint as officers advanced on Occupy protesters blocking an intersection during a May Day demonstration on May 1, 2012 in Oakland, California. (Justin Sullivan/Getty Images) # 

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Workers raise their caps as they march to salute Lagos State Governor Babatunde Fashola during workers rally to mark May Day in Lagos, Nigeria on May 1, 2012. Nigerian workers joined their counterparts in other parts of the world to mark May Day with a rally held in different parts of the country. The theme of this year May Day is "Right to Work, Food and Education: Panacea to Insecurity."(Pius Utomi Ekpei/AFP/Getty Images) # 

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People march down Spadina Street with the financial district skyline in the background as they take part in May Day protests organized by the Occupy Toronto and the No One Is Illegal groups in Toronto, on May 1, 2012. (Reuters/Mark Blinch) # 

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Riot police stand guard in front of the Rote Flora alternative cultural center during May Day demonstrations in the Schanze district in Hamburg, Germany, on May 1, 2012. (Reuters/Fabian Bimmer) # 

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A protester associated with the Occupy Wall Street movement is arrested while marching through traffic in lower Manhattan, on May 1, 2012. (Spencer Platt/Getty Images) # 

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Seattle Police officers gather near Pike Place Market, on May 1, 2012, during May Day protests in downtown Seattle, Washington.(AP Photo/Ted S. Warren) # 

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Protesters break windows during a rally for International Worker's Day, May 1, 2012 in Oakland, California. Occupy Wall Street has joined with unions during the May Day protests, a traditional day of global protests in sympathy with unions and leftist politics.(Eric Thayer/Getty Images) # 

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Militants and labour union members gather around a burning the effigy of Philippine President Benigno Aquino in Manila on May 1, 2012 as part of the May Day protests demanding higher wages and policies that would make it harder to fire workers. Aquino has said he is trying to help labour but has warned that giving too many benefits will make the country less competitive, costing more jobs.(Noel Celis/AFP/Getty Images) # 

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A protestor gestures to an Oakland police officer during May Day protests on May 1, 2012 in Oakland, California.(AP Photo/Ben Margot) # 

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A woman affiliated with Occupy Toronto is arrested for trespassing after she tried to erect a structure in Simcoe Park during May Day protests in Toronto, on May 1, 2012. The protesters were told by police they would be allowed to stay at Simcoe Park as long as they did not erect any structures. (Reuters/Mark Blinch) # 

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Police officers form a line during a May Day protest in Oakland, California, on May 1, 2012. (Reuters/Stephen Lam) # 

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A woman holding a sign marches past a line of police officers in New York, on May 1, 2012. (AP Photo/Seth Wenig) # 

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Protesters taunt police with donuts on fishing lines during an anti-capitalism rally on May Day in downtown Montreal, Quebec, on May 1, 2012. (Reuters/Christinne Muschi) # 

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A broken door, after it was damaged by a group of Occupy demonstrators during a May Day protest in Oakland, California May 1, 2012.(Reuters/Stephen Lam) # 

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Riot police watch as left-wing demonstrators march past Axel Springer headquarters during a May Day anti-capitalism protest on May 1, 2012 in Berlin, Germany. This year marks 25 years since a 1987 Berlin May Day demonstration turned violent and has been followed by clashes between participants and police on May Day in Berlin almost every year since in what has become an annual ritual.(Sean Gallup/Getty Images) # 

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An Occupy Wall Street activist with a bloody nose is arrested by New York City police during a May Day demonstration in New York, on May 1, 2012. (Reuters/Andrew Kelly) # 

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Members of the Tunisian General Labour Union, UGTT, demonstrate to mark International Worker's Day, or May Day, in Tunis, Tunisia, on Tuesday, May, 1, 2012 (AP Photo/Hassene Dridi) # 

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Demonstrators vandalize a Bank of the West branch during May Day protests on May 1, 2012 in Oakland, California.(AP Photo/Marcio Jose Sanchez) # 

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Protesters yell at police after arrests were made in downtown Miami, on May, 1, 2012, as activists marched from bank to bank demanding justice. (AP Photo/J Pat Carter) # 

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Tom Morello (center) of the rock band Rage Against the Machine marches with Occupy Wall Street demonstrators during a May Day rally on May 1, 2012 in New York City. (Monika Graff/Getty Images) # 

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A Seattle police officer wearing riot gear tangles with a woman after other masked protesters used bats and wooden poles to destroy the glass storefronts of several downtown businesses, during May Day demonstrations that went violent in downtown Seattle, on May 1, 2012. Several hundred demonstrators, including hundreds in black masks, hoods and armed with bats destroyed the windows of a Wells Fargo Bank, NikeTown and an American Apparel store during one of the numerous marches throughout downtown Seattle.(Reuters/Anthony Bolante) # 

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A mounted riot policeman rides his horse during May Day rallies in Santiago, Chile, on May 1, 2012. (Reuters/Ivan Alvarado) # 

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Indonesian workers march towards the presidential palace during the May Day protests in Jakarta, on May 1, 2012. Thousands of Indonesian workers held a peaceful rally in Jakarta on May 1 demanding better pay and a halt to outsourcing to contractors.(ADEK BERRY/AFP/GettyImages) # 

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An Occupy demonstrator is arrested during a May Day protest in Oakland, California, on May 1, 2012. (Reuters/Stephen Lam) # 

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A student demonstrator tries to stop fellow protesters from throwing stones and paintballs at riot policemen during clashes on International Workers' Day, or May Day, in Bogota, Colombia, on May 1, 2012. (Reuters/Jose Miguel Gomez) # 

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Los Angeles Councilman Bill Rosendahl (right) and Representative Janice Hahn (left) address members of the Service Employees International Union (SEIU) United Service Workers West labor union and their supporters during a protest on an one-day general strike at Los Angeles International Airport in Los Angeles, California May 1, 2012. Approximately 1,200 protesters took part in the demonstration to protest working conditions and to lend support to other May Day rallies. (Reuters/Gus Ruelas) # 

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Seattle riot police shoot pepper spray at masked protesters that used bats and wooden poles to destroy the glass storefront of an American Apparel store during May Day demonstrations that turned violent in downtown Seattle, on May 1, 2012.(Reuters/Anthony Bolante) # 

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A California Highway patrol officer stands near the Golden Gate Bridge waiting for possible May Day demonstrations in San Francisco, California, on May 1, 2012. May Day actions began with a strike by ferry workers Tuesday stranding commuters who usually take ferry boats to work. (Reuters/Robert Galbraith) # 

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A demonstrator yells during a May Day march on May 1, 2012 in Chicago, Illinois. About 1,000 people joined in the march which worked its way for about two miles from the city's West side into the Loop. (Scott Olson/Getty Images) #