The stunt cleverly tested—and demonstrated—a new dimension in which performance art can gain traction today: as content.

It's been 35 years since thieves stole more than a dozen works of art during a 1990 heist in Boston. It remains the most tantalizing art heist mystery in the world.

In 1990 thieves disguised as police stole 13 artworks from the Isabella Stewart Gardner Museum. Their empty frames have been ...