Boo-hoo. That couple deserves the social karma coming to them.
For what, buying land that legally went up for sale when a laughably low tax went unpaid for 40 years ? If this had happened anywhere else to people other than the ultra-rich, nobody would care and they'd be allowed to own it. This is nothing more than a demonstration of America being ruled by the whims of oligarchy rather than law.
The same result would have happened with anyone who could afford an attorney to pursue rescission of the sale.