Stonehenge 181
Image by Chance

>I have great sympathy with the idea of pinching them for their own good...<

Tell that to rock-art aficionados ;-)

I think the nicked stones (several in Lancashire) must end up in the gardens of rich crooks. If they're nicked and recorded on the SMR or with the Portable Finds Scheme, then there's an argument for positive intervention - particularly if they're threatened.