Graeme has kept his equanimity, even in the face of absurdity:
I have an Iranian stamp, a tourist visa from 2009. Like the United States, Iran includes a photo of the visa-holder on the visa itself. So they saw the visa, with all my biographical details and my photo and "Islamic Republic of Iran," and thought they were looking at the passport information page of an Iranian citizen. Pretty soon I was being dragged through the street like a deformed farm animal, and the people around me were yelling "Iranian! Iranian!" while I cried out in my best English in protest. We passed two cafés, and no one even bothered to take a shisha pipe out of his mouth to inquire about me.
The men ultimately delivered me to a government building on the Nile, where a man in a police uniform spoke English and confirmed that I was either a native English speaker with an accent appropriate to his nationality, or an Iranian with an unusually effective ESL teacher. He guessed the former and let me go, but not before telling me by way of apology that there are "foreign people in the crowds who want to create danger and kill Egyptians." He said roadblocks and crowds along the corniche were advised to hunt down "Iranians, Hizbullah, Qataris, Hamas, and" -- because why not? -- "Israelis.