Tens of millions of modern day Americans have a property-right interest in these particular estates if the Scottish Parliament acts in a way which renews ancient property rights.
Frankly I want my piece of the mountain and if some Socialist voting laird has been luxurating in Majorca while the land languishes in an unproductive state, then he'll just have to be evicted!
The sooner the better, too! - Him AND his sheep.
Go back far enough, and pretty much all land is owned by thieves and scoundrels. :>)
Seriously, though, there are a number of Scots families who have indeed owned their land for many centuries. The article above itself names one: John Mackenzie, whose family has owned 50,000 acres on the Isle of Skye for more than five centuries.
One or two MacDonald families own their ancestral land, as do a few families down south on the Borders. The Marquis of Lothian is an example, the Lord of Jedburgh. He is a Kerr, of Ferniehirst. A fortified house was built at Ferniehirst in 1476 by a Thomas Kerr, on an earlier foundation. The Kerrs still own it.