Well the 'accidental' damage to upland cairns is a major issue which has been the subject of debate on TMA across the years.. don't think we've ever achieved a consensus of opinion , certainly not regarding a solution... probably because there isn't any one solution.

The fundamental point I'd make is, no matter what reports such as these say, the damage isn't 'accidental'. It is vandalism, pure and simple. Picking up a stone or stones from an existing cairn and moving it somewhere else - even using the material to fashion another construction upon the cairn - is a conscious act. Not accidental. So what we are talking about is either:

1) Ignorance driving well meaning actions that nevertheless damage (in many cases) scheduled ancient monuments
2) Wilful damage to an ancient monument

Ignorance is no defence under law so both instances are, to my mind, crimes. However, clearly, it is impossible to police this except in fortuitous circumstances, so keeping tabs on your local area and reporting to the local authority, recording monuments for prosperity on TMA and other sites... basically raising awareness so 'ignorance' progressively becomes less of a defence... that seems the way forward for me.