BATF pushed at Waco, and got their butts kicked. I don't know what these agencies think they are accomplishing by following in ATF's wake, but unless you are working KNOWN CRIMINALS at a gun show--such a gig has to be a huge waste of law enforcement resources. In fact, working known criminals is the ONLY cost-effective/results-effective way to do pro-active police work, PERIOD.
The "gun culture" (a trendy leftist term that I'm ambivalent about using) showed me during 27 years of cop experience to likely be the most law-abiding and knowledgable groups of enthusiasts when it comes to knowing and following the laws associated with their hobby interest. Gun people DON'T BREAK THE LAW. If drivers acted like gun owners while on the highway, state troopers would get laid off by the hundreds, and car insurance would be a whole lot cheaper.