truck on the George Washingon Bridge 1

So, I'm having a delightful day with my dog Lizzie and my new camera on the George Washington Bridge when a security guard interrupts my reverie with the news that I'm not allowed to take pictures of the bridge. I'm not actually taking pictures of the bridge though. I've been photographing the traffic on the bridge but I sense the distinction will be lost on him. I ask if taking pictures from the bridge of the cityscape is permitted. Not that I'm really interested in taking pictures of the cityscape, just curious as to the parameters of this no photos rule. He says that one is not even allowed to physically bring a camera onto the bridge and that he could confiscate mine if he so chose. He's firm without being rude (just doing his job).