Judging by his website. Wouldn't the best approach be the softly softly one? He seems to see himself on a journey to enlightenment, part of this is what he does at the stones. I'm not condoning any of his actions, carving things, painting onthe stones, burying crystals etc. But he obviously cares about the sites (albeit in a bit of a different way to most people reading this) and might be open to people's reasonably put comments. And less open to being swooped on by angry people and the Law. On the spectrum of sanity I think he's a bit further towards loopiness than most of us. That's not an excuse but something a weedy liberal might want to take into account.