Lithuanian artist Redas Dirzys (R) and M

Lithuanian artist Redas Dirzys (R) and Mexican artist Enrique Jezik (L) carry images of former Mexican President (1968) Gustavo Diaz Ordaz and the then former Mexican Interior Minister Luis Echeverria, respectively, during a demonstration to commemorate the anniversary of the massacre of Tlatelolco, at the Plaza de las Tres Culturas, in Mexico City, on October 2, 2009. Thousands of Mexicans marched through the capital in memory of scores killed in a bloody student massacre there 41 years ago, in yet another call for justice. As student movements shook the world in 1968, Mexican security forces killed between 44 and 300 protesters in Tlatelolco, 10 days before the Mexican Olympic Games. AFP PHOTO/Alfredo ESTRELLA (Photo credit should read ALFREDO ESTRELLA/AFP via Getty Images)