There's many reasons not to stack rocks in nature. They mess with micro environments, create erosion, etc. But when I travel hours or days to a spot that is supposed to remain untouched by man/woman and see a buncha these things it people built for IG photos or whatever it kinda sucks. So if they feel the right to stack rocks, I reserve the right to kick them over. Simple as that.
Velcro on one side to stick to your headliner, jacket, or whatever else you can get away with.