1) it's not at securoty, border control, customs
These are the only places I dont take pictures in an airport. Everywhere else I do. Usually I take a pic when the coast is clear but sometimes it is impossible. One time when I got stranded at AGP I came back with 300+ photos, just at AGP. Many of these didnt have any people in as it was late at night and all the other flights had either gone or were about to go. I obviously understand that people dont like getting a picture taken without them asking.