Look at security this way. In most of the spots I've been at for training that were a base or detachment there were things in the field that you did not want people getting into. Range shacks or whatever.
So the first times there are a bunch of folks on the property they're supervised by CF members. But what about down the road when some of the Civi's come back on their own since they are now familiar with the lie of the land?
Airsoft, where nothing is hurt but feelings.