In the late 1980s, London's National Gallery got a new wing thanks to a donation from Lord Sainsbury and his brothers. He objected to false columns added by the architect, Robert Venturi, but had no formal authority to overrule him. Instead, he hid a letter inside one of them thanking whoever was finally removing them. They were removed, and the letter found, 34 years after the wing was opened.
The text of the letter, replete with Lord Sainsbury's ALLCAPS energy, follows.
IF YOU HAVE FOUND THIS NOTE YOU MUST BE ENGAGED IN DEMOLISHING ONE OF THE FALSE COLUMNS THAT HAVE BEEN PLACED IN THE FOYER OF THE SAINSBURY WING OF THE NATIONAL GALLERY. I BELIEVE THAT THE FALSE COLUMNS ARE A MISTAKE OF THE ARCHITECT AND THAT WE WOULD LIVE TO REGRET OUR ACCEPTING THIS DETAIL OF HIS DESIGN.
LET IT BE KNOWN THAT ONE OF THE DONORS OF THIS BUILDING IS ABSOLUTELY DELIGHTED THAT YOUR GENERATION HAS DECIDED TO DISPENSE WITH THE UNNECESSARY COLUMNS.
The current renovations are controversial (making the foyer look like "a third-rate office park") but the unnecessary columns (pictured here) were plainly horrible and seem to have been a target of mockery.
Here's the letter itself.
Sainsbury died before they were removed, but after plans for their removal were made. So he died happy. About that, anyway.