My own flasher story was a little amusing (in hindsight), but I've been hearing others that trump mine completely. My friend D, who has lived here more than a decade, once was jogging around the Gezira Club. A man dropped his pants in front of her and threw himself to the ground and gyrated. She jogged the other direction, but this was the end of her jogging career in Cairo.
Another person told me of a man-of-the-people flasher. An older man stood in traffic and lifted his robe up and then put it back down. Over and over. He wasn't singling out foreign women. He was flashing everyone!
Then a professor at the American University of Cairo told me how his 14-year-old daughter had been flashed by a taxi driver in Ma'adi. The driver had a single front tooth that stuck straight out and a gray streak of hair above his right ear. Had this been the same one that had flashed another young girl the week before? Perhaps not, but in that case there must have been a flashing epidemic in Ma'adi. The 14-year-old was quite upset, so the family had reported the incident to the police.
A few days later, the professor's wife had jumped into a taxi and voila... the driver fit the description! She gave him directions to the police station, then asked him to wait while she went inside. She came back out, but brought the police with her to arrest the man so keen for exposure.
The disturbing question that no one really likes to think about is "What do the police do to these people?" They probably beat them up and let them sit in jail for a few months. I don't know if I would go through with the police reporting part if it was just me being shocked at the sight of a naked male stranger, but then, if that 14-year-old was my kid, I'd report it in a... flash.