I know this topic has (naturally enough) spread to the general protection of sites but I was reffering to Skara Brae in particular as this is a lot more fragile site that say Stenness / Brodgar / Avebury etc etc.

Not only could damage be done to the stone furniture very easily, it wouldn't actually take much effort to steal the stones from the furniture etc!
Anyone could approach from the beach and take stones away without being seen.

I appreciate this is all unlikley to happen it's just at this particular site it struck me how easy it would be to damage / steal from such an important location.