Dont have that problem but many, even 'shooters' dont understand range protocol, esp the firing line and what it means. Two summers, twice. while I was shooting someone arrived and decided to go downrange and post targets. There had been no discussion between us in either case. I had read about this on forums and thought it was BS, but it happens.. The one fellow when asked about it said "go ahead and shoot!!"
I wasnt going to shoot when he was downrange but I was worried about what he'd do when I was downrange...yuk!
We have a fellow that like to come to the range (public/unattended/DNR) and mine the backstop. We see piles of sifted dirt there many days. The problem is everytime it rains hard that loose stuff comes washing down the hill. Soon we have to try to get the DNR to bring the frontend loader over and repile the backstop.