In the 1970s Richard Prince became known as a pioneer in "appropriation art" by photographing other photographs, usually from magazine ads., enlarging them and exhibiting them in art galleries. One of his photographs from a Marlboro ad sold by Christies for $1.3 million, a record for any photograph. The original of this picture as well as another copied by Richard Prince which sold for $332,000 by Christies, was taken by Richard Krantz on assignment for Marlboro cigarettes ads. Mr. Krantz and others whose photographs Mr. Prince has "borrowed" have expressed concern over this use of their work. Mr. Krantz's advertiser clients in most cases own the copyrights to the photographs copied and sold as art by Mr. Prince. The Guggenheim Museum in New York is currently holding a 30-year retrospective of Mr. Prince's work.

The NY Times article by Randy Kennedy 12-6-07 linked below raises interesting questions about the nature of art, fair use and copyright protection. Apparently the working definition of art in the art auction and museum world includes photographs copied from the work of other photographers.

http://www.nytimes.com/2007/12/06/arts/design/06prin.html?_r=1&ref=arts&oref=slogin