That the Zabaleen are mostly ethnic Copts, because Muslims don”t handle garbage. For all that, they were not very good Christians, being sunk in drugs and alcohol and the like, until a preacher named Abu Samaan came in and helped clean things up, at least ethically, and revived the Faith. He also caused a beautiful church to be carved out of Mount Mokattam, which rises just behind the Garbage City. During the swine flu epidemic a couple years ago, the police came in and slaughtered all their pigs, a vital part of the recycling work, and a month ago, after the Revolution, an Islamist mob attacked the Garbage City and people were killed. Life is riskier now for the Copts, in general, than it was under Mubarak.
Related: “Garbage City Cairo“