One way of not allowing others at the range to fire your guns, is keep to yourself and dont try to socialize, then they wont ask, the more you talk the more likely they will want to shoot your guns, sometimes they keep talking and talking wasting your time, talking about gun laws , politics, personal problems, etc
I try to stay away from the chatter box range rat types, they spend too much time talking instead of shooting.
the last time I was at the range a guy walks from the far end of the range to see what Im shooting asking a bunch of questions then he puts his dirty hands on my rifle without my permission touching the sights with dusty hands from picking brass off the ground and leaves dirty hand prints on my rifle.