QENA, Egypt—Five weeks after the fall of the Egyptian regime, Ayman Anwar Mitri's apartment was torched. When he showed up to investigate, he was bundled inside by bearded Islamists.

Mr. Mitri is a member of the Christian Coptic minority that accounts for one-tenth of the country's 83 million people. The Islamists accused him of having rented the apartment—by then unoccupied—to loose Muslim women.

Inside...