Protesters throw a petrol bomb against riot police during a student's rally which marks the fourth anniversary of a deadly police shooting that triggered major riots, in the northern Greek port city of Thessaloniki, Thursday, Dec. 6, 2012. Fifteen-year old Alexandros Grigoropoulos was shot dead by police in central Athens on Dec. 6, 2008, sparking riots in Greek cities that lasted nearly three weeks. The police officer convicted of the shooting was jailed for life in 2010. (AP Photo/Nikolas Giakoumidis)
