We report a laboratory experiment in the context of the December 2008 riots in Greece, after the killing of a 15-year-old student by a policeman. Our sample comprised 266 students from the University of Thessaloniki. We tested whether media reports can affect people’s willingness to harm those in opposing groups by examining the way students allocated money between themselves and others of various professions, including police, in modified dictator games. Exposure to media reports decreased giving to police, but only when choices were private. Laboratory behaviour was correlated with self-reported participation in demonstrations, supporting the external validity of our measure. Media exposure appears to have affected behaviour by different pathways than those proposed in the existing literature, including “spiral of silence” and “frame alignment” theories.