That's the core problem. Generally speaking, when you've got some questionable/debatable restriction like that, you want to err on the side of being permissive rather than restrictive.

But the way we do things now just happens to be the way they are done. For instance, there could be restrictions on where and when you're allowed to advertise, and how you're to present the information. I'm not saying that's the way things should be done, just that alternatives to the status quo are not necessarily infringing on your rights.