Yesterday, a US District judge decided against Richard Prince, Gagosian Gallery, Lawrence Gagosian and catalogue publisher Rizzoli in a case about appropriated imagery.

In January 2009, French photographer Patrick Cariou alleged that Prince incorporated images from his book, Yes Rasta (2000, Powerhouse), into works for a 2008 show at Gagosian in New York, without permission. Cariou spoke to A.i.A. via telephone from Paris: "Everyone is ecstatic, my phone is ringing off the hook, I've gotten hundreds of emails. People seem to be on my side, at least the ones who make the effort to contact me," he said.

Judge Deborah Batts ordered the defendants to destroy remaining copies of the catalogue and unsold paintings that make use of Cariou's photographs. They also must inform any collectors who own the offending artworks that it is now illegal to publicly display the paintings. How, exactly, this will be enforced is unclear.

Copyright cases are notoriously difficult to prosecute. National fair use laws say that a new work must transform or comment on its source material. According to a 2008 press release, the paintings "provide an anarchic tropical scenario in which extreme emanations of the (white American male) id—fleshy female pin-ups, Rastafarians with massive dreadlocks, electric guitars, and virile black bodies—run riot."

In court, Prince testified that he "didn't really have a message." The judge responded, according to courtroom reports, by assessing, "There is vanishingly little, if any, transformative element."

One of the factors that determines fair use is the amount and substantiality of the portion of the copyrighted work used. Prince used 41 photos from Cariou's book, some printed directly onto the canvas, others applied with oozing paint. Back to the Garden (2008) is a canvas printed with a black-and-white Cariou photo of a Rastafarian riding a donkey, to which Prince added via collage another reproduction of the same Rasta, and two topless pin-up girls. Some of the eyes and mouths are covered with white painted orbs.

Cariou said Prince had not reached out to him, or tried to explain his work. It remains to be seen how this lawsuit will affect other appropriation artists, and whose responsibility it is-the artist or gallery-to prove that appropriated material falls under fair use.

"This lawsuit is about arrogance, laziness and an overwhelming sense of power. It has nothing to do with art," Cariou told A.i.A. "At the end of the day, he took 41 pictures—it's not just one little part. It's almost half of the book. I really don't understand how he thought he could get away with it."

A Gagosian Gallery representative did not respond immediately to a request for comment.