Migrants from Central America wait for a freight train after taking part in a protest in Lecheria, in Tultitlan, Mexico on May 17, 2012.

A Central American immigrant waits for a chance to board a train in Tultitlan on May 17, 2012.

Honduran Reina Jackeline, who is six months pregnat, rests near a passing train in Tultitlan on May 17, 2012.

A student protester in a panda suit confronts a policeman in downtown Montreal on May 17, 2012. The students are striking over a planned tuition hike of 82 percent or over $1,700 as part of the government's efforts to rein in a budget deficit.

Policemen restrain a student protester.

Palestinian women scuffle with Israeli policemen as they try to stop them from arresting a relative in the east Jerusalem Arab neighborhood of Issawiya on May 15, 2012, as Palestinians took to the streets to mark Nakba day.

A Palestinian suspected of throwing stones is detained by undercover Israeli police officers in the East Jerusalem neighbourhood of Issawiya May 15, 2012.

A boy holds up a door key as Palestinians take part in a rally marking Nakba in the West Bank city of Ramallah on May 15, 2012.

A Palestinian youth shoots fireworks at Israeli policemen in the east Jerusalem Arab neighborhood of Issawiya on May 15, 2012.

Israeli riot policemen arrest a Palestinian boy in the east Jerusalem Arab neighborhood of Issawiya on May 15, 2012.

The head of Gaza's Hamas government, Ismail Haniya (blue polo shirt), takes part in a marathon in Gaza City on May 15, 2012 to mark Nakba day.

A woman holds a card reading "This bank cheats, defrauds, throws people out of their houses" during a protest held outside Caja Madrid bank's headquarters in Madrid on May 14, 2012.

Riot police stand guard in front of a branch of the recently nationalized Caja Madrid bank during a protest in Madrid on May 14, 2012.

Thousands of police officers march in London, Britain, on May 10. Over 30,000 police officers marched through the capital protesting against government cuts to the police force. Hundreds of thousands of public sector workers also took part in a national strike in a dispute with the government over pension changes.

Off-duty police officers march in protest at funding cuts through central London on May 10. Thousands of British police officers planned to join striking border officials and healthcare workers on Thursday in a protest against wage caps, pension reforms and other austerity measures.

Off-duty British police officers march through central London, on May 10, in a protest against proposed changes to their pay, conditions and staff numbers. Hundreds of thousands of British public sector workers were set to strike over pensions Thursday and police were due to protest against Prime Minister David Cameron's austerity measures.

Kashmiri government employees are sprayed with purple colored water by Indian police to disperse a protest in Srinagar on May 9.

Indian police in Srinagar on May 9 used a water cannon and batons to disperse hundreds of government employees while detaining dozens as they attempted to reach the civil secretariat.

Petitioners protesting about medical and land grab issues are detained by police outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8.

A petitioner, allegedly persecuted by local officials after reporting a corruption case to the central government, shows a scar, trying to attract public attention for his case, while he is grabbed by a policeman outside the hospital where blind activist Chen Guangcheng is staying for treatment in Beijing, China, Tuesday, May 8.

A petitioner amongst a group protesting about medical and land grab issues is detained by police outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8. Blind activist Chen Guangcheng said May 8 he has met government officials about getting a passport, raising hopes he may soon be able to leave China, but US embassy staff still cannot visit him in hospital.

Security guards talk outside the Chaoyang Hospital where blind Chinese activist Chen Guangcheng is being held, in Beijing on May 8. Blind activist Chen Guangcheng said May 8 he has met government officials about getting a passport, raising hopes he may soon be able to leave China, but US embassy staff still cannot visit him in hospital.

Landless people hurl stones towards riot police during a clash in Katmandu, Nepal, on May 8, 2012.

Police arrest landless squatters who live beside the Thapathali hospital during clashes with police personnel who arrived to demolish illegally-built houses in Kahmandu on May 8, 2012.

A girl who used to live beside the Thapathali hospital cries during the clashes in Katmandu on May 8, 2012.