If they stop you, it was never your property to being with. See my tagline.
You're right; ownership has never been all that absolute. Nowadays, they tend to describe ownership as a bundle of rights that a person has with respect to property. They want you to picture a little bundle of sticks, each one representing a right to do something with regard to the property. Here and there, the government comes along and takes a stick out or puts another one in - more taking out than putting back in lately, I'm afraid. ;-)