Quote from : The Sirens of Titan Book

Rumfoord had known that Constant would try to debase the picture by using it in commerce. Constant's father had done a similar thing when he found he could not buy Leonardo's "Mona Lisa" at any price. The old man had punished Mona Lisa by having her used in an advertising campaign for suppositories. It was the free-enterprise way of handling beauty that threatened to get the upper hand.