Men step on the image of U.S. President Barack Obama printed on a U.S. flag during a rally in Karachi September 29, 2012. According to local media, thousands of supporters of various religious parties march through the streets of Karachi against an anti-Islam film made in the U.S. mocking Prophet Mohammad. REUTERS/Athar Hussain (PAKISTAN - Tags: POLITICS CIVIL UNREST RELIGION)