Two years ago the Egyptian city of Cairo, the largest city in the Arab world and the "timeless city" of Obama's Cairo speech, the heart of the Arab Spring, was suffering from a garbage crisis. The crisis had a very simple cause, the pigs that used to eat the garbage were killed to prevent the spread of Swine Flu.
The pigs living in "Garbage City" had served as both organic garbage disposals and food sources for the Zabaleen, families of marginalized Christian Copts who made a living by collecting the garbage, reselling the inorganic garbage and feeding the organic garbage to pigs. The system worked fine so long as there were pigs, but without the pigs, Cairo's streets are filled with giant mounds of rotting garbage.