It could be argued that Pop Art began with Mickey Mouse. In 1960/1961, one of Roy Lichtenstein's sons pointed to a Mickey Mouse comic book and challenged his father to create something better. Around the same time, Andy Warhol drew Mickey Mouse along with Dick Tracy and Nancy. Warhol's Nancy was one of his first Pop works, a painting he gave to Ivan Karp as a gift in 1961. By the mid-1960s, Joe Brainard made Nancy his own, yet he also on at least one occasion incorporated Mickey Mouse into his work. Mickey Mouse appears in the Brainard/Creeley collaboration Class of '47.
So who cares? Well, copyright law have been re-written in order to cater to Disney and Mickey Mouse. See http://dir.salon.com/story/tech/feature/2002/02/21/web_copyright/index.html. It is ironic that Lichtenstein and Warhol would latch on to the image of Mickey Mouse to divorce themselves of artistic intention, to further the impersonality of the artist, when the desire to protect the image of Mickey Mouse would create the need to extend the copyright rights of authors and artists for another two decades, thus preventing such appropriations from happening. But really it has nothing to do with protecting artists and authors at all, the key to this copyright "reform" was protecting the profits of large corporations.
Pop Art building off of Duchamp complicates issues like copyright, plagarism, originality, authenticity, trademark, and corporate branding. Lichtenstein, Warhol and Brainard were aware that the history of 20th Century Copyright is the history of Mickey Mouse and the comics. See http://www.techdirt.com/articles/20090811/0123105835.shtml Pop Art far from being superficial is intensely aware of art history and is as intellectual as the Abstract Expressionism that comes before it.