Thanks for the advice guys. Gonna contact the various town councils and just sent a heritage alert.
Maybe I'm just a naive wiltshire lad, but personally i cannot believe they'd let ilkley moor's flagship site get destroyed like this. If I get no action from the town councils etc, and if no one is responsible for it, I am definitely of the mind to think 'bugger it' and head off up there with a bag of cement, some spades and dig it up and re-seat the stones and fix up some of the damage.
if the stones arent in their original positions anyway, it wont matter. Just so long as a stone circle remains up there for another generation to enjoy.
I'll go the council route first....then see if I've got the energy left for the "buggrit" route...
:-D