This article from Art Law department at Harvard explains that artists have certain rights within the creation of their works.  One-way is through appropriation art: the quoting of work from other artists.  Artists borrows elements from the original that may stay completely unchanged, however, the new work uses the original to create something new.  Appropriation art took place as far back as Raphael’s Judgment of Paris c.1515, which was since lost but one of the artist’s employees, Raimondi, made an etching of it, which proceeded to be copied over and over.  Three centuries later, Manet took part of this image and inserted it into his painting, Le Dejeuner Sur L’Herbe.  A century later, Picasso translated Manet’s work in a series of paintings.   Thus, artists’ have always relied on being inspired and influenced by earlier works.

The Roger v. Koons (1992) case, wherein Jeff Koons commissioned a sculpture of Art Roger's photograph postcard, and in so doing, violated Rogers’ copyright of his original work, is regarded as the primary modern day case of appropriation art.  Koons’ work copies the original exactly, although the puppies are painted a vivid blue, have bulbous noses, and the two figures are decorated with three flowers, which does not occur in the original.

Koons has been in a number of cases in which he has tried to argue for parody or satire, for example, in order to deem his work transformative enough from the original, and thus fair use.  Appropriation art is a major get-out-of-jail free card, that gives artists the ‘artistic license’ that is arguably essential in creating great works, as exemplified by the fact that the most well recognized artists have been doing this for centuries.