Just Stop Oil vandalise Stonehenge by spraying it with orange paint.

The point is to force public attention back onto the subject of global warming and also drive up recruitment for more substantive actions (e.g. blocking coal plants) that screw over fossil fuel companies directly. Also, they like to do outrageous shit as a way of sorta pointing out how much more outrageous our climate policies are in comparison. "You're mad about some rocks getting spray painted but you're not mad about our government indirectly killing hundreds of millions of people and creating the worst refugee crisis in world history."