Public photography (at least in the U.S.) isn't just constitutionally protected because it is a form of expression (art), but also because it is an exercise in

Public photography (at least in the U.S.) isn't just constitutionally protected because it is a form of expression (art), but also because it is an exercise in free press. In the U.S., anyone can be free press, and as such can document any goings on in public, including photography.