As they probably get all their self-validation from social media they might have a bit of a shock when people start sending them unkind messages. People get death threats for less.

Natural justice would be to push them off though, I can't say I wouldn't get a bit of satisfaction out of that. But it's nice to think they might eventually repent and regularly experience the most excruciating guilt and embarrassment for the rest of their lives every time anyone mentions a rock, or grit, or stones, or sees anything falling, or hears "weren't you that idiot who vandalised Brimham Rocks"? You know that sick to the pit of your stomach feeling you get when you remember something trivial but embarrassing from your youth. But much much worse.