The Cornish have longed been accused of wrecking and even today there are some activities the police frown upon. A cargo vessel which was grounded a few years ago had several BMW motorbikes disappear before the authorities arrived and one unfortunate sailor whose plush yacht washed up in the 80s I recall, sat in his yacht whilst people swarmed over it and even unscrewed fittings before his eyes. By the 1980s though I would assume most of those people were not Cornish.
The Cornish themselves deny ever having deliberately wrecked a ship by putting false lights on hills on stormy nights and attracting the wooden ships to the rocks. They do admit that they believe a ship grounded is fair game on the basis that salvage is maritime law and they would sell the articles back to the owners if they ever asked.
In recent years the funniest wreck was a vessel carrying wood, and the police cited seeing huge timbers being ferried away by large vehicles and some enterprising graduates at Plymouth university built on the rocks a perfect bungalow for visitors without using a single nail or screw. Of course someone had to take a picture of it and it appeared in the papers so was dismantled. Planning laws don’t like things built below cliffs.
If you find salvage you are supposed to tell the authorities. But then supposed is an empty word and the people are people.