There used to be a dealer who brought his own CCTV system to the convention with him that he set up to monitor and record activity at his own table. (Ironically, that dealer's name was since-departed club members, Vince & Betty Mowery.) This simple type of closed circuit surveilance set-up during show hours might be an alternative prudent action to take by other convention dealers as well.
Also; name tags on convention visitors this past year were 99.9% accurate as all visitors to the convention (members and non-members alike) had to show positive photo i.d. to the Registration Committee in order to get their name badges issued. (**No more "Mickey Mouse" or "Donald Duck" registrants are accepted.)