I think Megadread is right Olly, no one is saying that people should'nt go there and have ceremonies for whatever reason, but what is being said that there should be no damage to the site. For instance at Man an Tol in Cornwall people were burying resin 'taliesmans' around the stones; you have to have some sort of law to protect sites from such happenings, such as painting on stones, or chipping bits off...