I really think about 70% of it is BS that the "security guard" takes it beyond his scope of authority. I ran into a similar situation with a metro cop telling me I couldn't take a shot of an office building. All I did was say, "I'd like to speak with your supervisor, please." Immediate back-down. He said, "Uh... uh... never mind". At that point, I *insisted* for his sergeant. He said no need for that. "Fine," I said, "I'll call him myself. I've got your badge number and last name." At that point, sweat started popping profusely and he called the supervisor on scene. I told him what happened, the cop even backed up what transpired, and was reprimanded on the spot and I was apologized to for a "over-zealous rookie". I have all the respect in the world for cops. I would NOT want their job. But, some of them get just a little stupid sometimes and need to know that not everyone is ignorant and complacent.
---- "The best camera is the one you have with you."
Pentax K-70 ~ Panasonic FZ1000