Hi Dave,
My beef is the same as yours, a trade/merchant show makes its way to the public at large via camera phones and You Tube. Short of confiscating every cell phone at the door I don't know how you avoid this situation. Clearly, there needs to be more vigilsnce about who they let in.
It's just the way things are now, but, in knowing that, I would have thought that any manufacturer allowing a work-in-progress unit to be displayed would have had serious second thoughts about showing their hand, so to speak. Dodgy decision in my book.