Some years back a similar policy was announced by the National Park System. Depending on the park and the particular ranger you encountered it was seldom enforced against individuals. If, however, you showed up with a film crew with all the attendant equipment, they were sure to jump all over you. Or if you made a pest of yourself, blocking access to areas with your tripod, etc; demanded others get out of your picture; were unsafe; or invaded restricted areas, you would probably (and should) be hassled and forced to obtain the requisite permits and abide by every rule they can find. I have heard of individual or small photographer groups being hassled, but believe it is pretty rare.