Carefully balanced rock towers make a pretty picture, but the proliferation of cairns, fuelled by social media, has negative consequences for the environment.
national park visitors are stacking stones for their instagrams, and it's ruining the parks--an example of how social media is "transforming an activity that would be mostly harmless in isolation into something with planetary impact" via
I wrote for about stone stacking, which is an ancient tradition, except then someone figured out you can take nice pictures of them, and then other people did, and now people are stacking too many stones!!! It is causing some problems!