Riot policemen stand guard after getting splattered by paintballs from student protesters during clashes on International Workers‘ Day, or May Day, at the central square of Bogota May 1, 2012. (REUTERS/Jose Miguel Gomez)

Riot policemen stand guard after getting splattered by paintballs from student protesters during clashes on International Workers‘ Day, or May Day, at the central square of Bogota May 1, 2012. (REUTERS/Jose Miguel Gomez)