Depending on the clubs rules ( all are slightly diffrent diffrent) members have the right to "card" others for reasons of keeping the club grounds secure. At the club I belong to it isnt unusual for people to follow members thru the coded acess gate, or one thats open for equipment / contractors and use the facilities. They can be a real problem as even though they arnt members the club is responsible for the results of their actions. Our back stops are sand and digging in them will increase the amount of erosion. We have tried to get grasses and difrent things growing on it to help hold the sand in place. At this club everyone is a "range officer" . Personally You dont want to show me your members card when I ask politly to see it I have no problem calling the board members and or sheriff. Show a temper tantrm Ill call the sheriff for saftey reasons also. No Im not a busy body but I do want a safe enviroment and having been a officer I know what the club has went thru with the above issues.