I attended the Big Town gun show this last Saturday. After my initial recon. I headed out for a break. I observed a Mesquite police officer talking to a gunshow attendee. I was just a few feet away and heard the relevant parts of the conversation. The LEO was writing the guy a trespass warning. If he returns to the area again it's an arrestable offense. Apparently the organizers require that anyone who has purchased a firearm there to show a receipt when they exit the building. I'm not sure how they can tell who has bought a firearm at the show or if they are leaving with a gun they are trying to sell. I sold mine within 10 minutes of walking the aisles. The LEO was very professional in dealing with the citizen.