Was picking up my CMP Garand yesterday from the FedEx office, and as I parked, I saw a little 2"x2" sticker with a pistol and a knife with a circle slash over them. (My first reaction was to laugh, I was there to pick up a rifle, but I digress.)
I said I think, because from my understanding, such a posting is not compliant with the posting requirement under the law, therefore, though it was visible, since it wasn't posted properly it had no legal authority.
Regardless, we know how FedEx feels now.