That doesn't mean you won't be hassled for doing something legal. Example: There is no law against taking pictures in public yet many cops and security guards will tell you otherwise, citing the "9/11 rules". There are no such general rules. There are explicit laws pertaining to some military bases and nuclear power plants. In one famous instance a motorcyclist was charged with wiretapping... because that was the closest thing they could find pertaining to the helmet cam video he posted to youtube. The video contained audio, you see... The charges were eventually tossed by a judge, but I wonder how much it cost the motorcyclist in legal fees to get that far.
My favorite was the on film video of security guard telling a TV camera crew they could not set up in a transit station as they were getting ready to interview the transit spokesperson explain how it was not illegal to take pictures in the station.