Until very recently few had ever heard of Yellowism, an art movement that gained some notoriety in October 2012, when self-proclaimed Yellowist Vladimir Umanets wrote on one of Mark Rothko's paintings at the Tate Modern. Umanets signed his name on Rothko's "Black on Maroon" and also wrote the phrase “A potential piece of yellowism." It is difficult to discern exactly what Yellowism is, though there is a website for the movement as well as a YouTube channel. Blouin ArtInfo gives a critical, but thoughtful analysis of Yellowism here.
Marcin Lodyga, Umanets' partner in Yellowism wrote that Rothko's painting at the Tate, signed by Umanets was still a work of art. He felt it would not be Yellowism, only potential Yellowism, until the work was placed in "yellowistic chamber," at which point it would express only the color yellow and cease to be a work of art. Umanets told the BBC, "Art allows us to take what someone's done and put a new message on it."
Rhetoric aside, appropriation within the art world is not new. Marcel Duchamp signed a urinal and transformed an industrial design into a work of art. Artists like Andy Warhol and Jasper Johns incorporated images (trademarks included) from modern culture into their works as if casting a mirror out onto modern society. However, at some point in the 1970s and continuing until today art began appropriating itself, in the form of physical "attacks" on existing works displayed in galleries and museums.
These "attacks" present some very unique legal questions. When someone writes on a Rothko painting or dumps a bottle of ink into Damien Hirst's pickled sheep or draws a clown face on a Goya print, does this act of destruction create a new work of art and with it new copyrights in another author?
Copyright protects original works of authorship, giving the author exclusive rights and the ability to prevent unauthorized copies or otherwise derivative works. As for art attacks, it would seem that the question comes down to whether the new work would be seen as an unauthorized derivative, or whether the work was transformative enough, and accordingly leaning in favor of fair use. Still, transformative use is an incredibly difficult question, and often it leaves much to the eye of the beholder.
One must also consider the moral rights attached to certain works. In most civil law jurisdictions and some common law jurisdictions, moral rights attach to works of art during an artist's lifetime. Among other issues, moral rights protect the integrity of the work, barring alteration, distortion, or mutilation of the work even after it leaves the artist's possession or ownership, and even if the artist has assigned the copyrights to another. While moral rights may not present an issue in the case of long-since deceased artists, they could certainly play an important role in attacks on the works of living artists.
Further, it seems that in most cases those who "attack" works of art are not the legal owners of the physical work of art, thus their acts constitute crimes as well as civil torts. Even if a new copyright existed, it would likely be rendered worthless as proceeds from the copyright would be viewed as proceeds of a crime. (In case anyone is still wondering, Umanets was arrested for what he did to Rothko's painting.)
While art attacks might serve as an end run into the limelight for new artists, the social and legal consequences are considerable.