A University of California Davis police officer pepper-sprays students during their sit-in at an “Occupy UCD” demonstration in Davis, California November 18, 2011. UC Davis Chancellor Linda Katehi apologized to jeering students on November 21 for police use of pepper spray against campus protesters in a standoff captured by video and widely replayed on television and the Internet. Faculty and student critics of Friday’s confrontation, some of whom demanded the chancellor’s resignation, said it had damaged the school’s image and the climate for free expression at the university. Photo taken November 18, 2011. REUTERS/Brian Nguyen (UNITED STATES – Tags: CIVIL UNREST EDUCATION CRIME LAW TPX IMAGES OF THE DAY)