But whatever the outcome, the tiff has served to highlight the power and privileges enjoyed by the heirs of creative artists. They may have no artistic talent of their own, but they bask in reflected glory, receive royalties and determine how works are interpreted or exploited.

In the European Union, as in most copyright protection in the United States, inherited “moral rights” last for 70 years after the death of the artist, so the greats of the more distant past are open to all sorts of license. A Shakespeare play can be updated to the American South, a Mozart opera can be set in Trump Tower, Marcel Duchamp can add a mustache to the image of Mona Lisa — and no one can object.

But when it comes to writers and artists who have died since 1937, legal heirs, not always direct descendants, have the last word.

In the visual arts disputes often arise when an image is used commercially without permission. Thus the Picasso estate spends a lot of time trying to chase down the illegal use of Picasso drawings or paintings on everything from coffee mugs and T-shirts to posters and prints, while simultaneously selling his name for use on the Citroën Xsara Picasso car. René Magritte poses a different problem. Although his Surrealist images are also reproduced without authorization, more often they inspire advertising images, like figures floating in the sky borrowed from the bowler-hatted men in “Golconda.” But when an idea, not an image, is lifted, it is not protected by copyright.

Salvador Dalí’s extraordinary imagination is no less plagiarized, but he got ahead of the game by commercializing his own images to the point that André Breton turned Dalí’s name into an anagram, Avida Dollars. And if fake Dalís abound, it is also because he is said to have signed hundreds of blank sheets of paper before he died in 1989.