It might be a little hard for them to post all possible prohibitions where people could readily see them. Sometimes you see things like "No Eating in the Common Areas" and things like that, but it's pretty hard to anticipate everything they might encounter.

The way malls are usually set up is that the mall is owned, or at least managed, by some real estate management agency that leases space to individual businesses. They probably didn't tell the T-shirt shop what kind of T-shirts they could or could not print up and sell. Nor would they tell, say, a Radio Shack outlet what equipment they could sell. But should someone buy a bloody-great boom-box at the Radio Shack outlet, then go out in the common area of the mall with the boom-box turned on and cranked up, the mall management would be within their rights to insist that the customer turn it down, shut it off, or leave the mall. What the individual stores sell is, literally, their own business, although the mall management can exercise control there, too. You usually won't find a porn shop in a mall, because the mall management won't lease to them.   What the customer does in the common areas of the mall does fall under the jurisdiction of the mall management and security.

Frankly, I think they are being pretty damned snotty about the T-shirts, but that's because I sympathize with the T-shirt wearers' message. I wonder how the mall management might react if a couple of people walked through the mall wearing, say, swastika armbands. If they told them to take 'em off or get out, I don't think most of us would object. But there again. . . .

How people react seems to depend on whose ox is gored.

Don Firth