Is this theft or homage?

IN February 2007, the Swiss-American artist Christian Marclay was installing a solo exhibition of his work in Paris when he received an e-mail from a friend about a commercial for the Apple iPhone that had been broadcast during that year's Oscars.

The 30-second spot featured a rapid-fire montage of clips from television shows and Hollywood films of actors and cartoon characters – including Lucille Ball, Humphrey Bogart, Dustin Hoffman and Betty Rubble – picking up the telephone and saying "Hello". It ended with a shot of the soon-to-be-released iPhone.

Marclay tracked down the ad on YouTube and watched it. "I was very surprised," he says. Like many in the art world he saw an uncanny resemblance between the iPhone commercial and his own 1995 video Telephones, which opens with a similar montage of film clips showing actors answering the phone. That seven-and-a-half-minute video, one of Marclay's signature works, has been exhibited widely throughout Europe and the United States.

About a year before, Marclay says, Apple had approached the Paula Cooper Gallery, which represents his work in New York, about using Telephones in an advertisement.

"I told them I didn't want to do it," he says. His main concern, he says, was that "advertisers on that scale have so much power and visibility" and that "everyone would think of my video as the Apple iPhone ad."

Marclay says he spoke with a lawyer after learning of the advert but decided not to pursue legal action. "When people with that much power and money copy you, there's not much you can do," he says. In any case, he did not want a controversy to draw attention to his own appropriations of scenes from other sources – mostly Hollywood movies – without permission from the copyright holders.

"I don't consider what I do stealing," Marclay says. "I'm quoting cultural references that everyone is familiar with. I make art that reflects the culture I live in." And unlike advertisers, he says, "I'm not trying to sell phones." Neither Apple nor its advertising agency, TBWA/Chiat/Day, would comment on the iPhone ad.

Artists have been appropriating images from advertising for decades. In the 1960s, Andy Warhol made silk-screened copies of Brillo boxes and Campbell's soup cans. In the 1980s, Richard Prince rephotographed magazine ads for Marlboro cigarettes, enlarged the pictures and exhibited them as his own. Works like these are comments on consumer culture that also challenge the idea of originality itself.

But what happens when the tables are turned? In recent years, a number of campaigns have seemed to draw their inspiration directly from high-profile works of contemporary art. And the artists who believe their images and ideas have been appropriated are not happy about it.

Donn Zaretsky, a lawyer who specialises in art law, is often approached by artists who perceive echoes of their own work in advertisements. "It does seem like advertising people are pushing the envelope on this," he says. "They're being more and more brazen in their borrowing. On the one hand, they should be mining the art world for inspiration, and you would expect them to be referencing works that people are familiar with. But more and more, they seem to be getting into the territory of blatant rip-offs."

The law governing the unauthorised use of copyrighted images and ideas, he says, is notoriously murky. "Copyright law doesn't protect ideas, it only protects expression. The question is, where do you draw the line? Is the agency being inspired by the idea? Or did they copy the artist's expression?" When artists go after advertisers in such cases, the disputes are most often settled out of court. There have been a few notable cases in which artists successfully sued advertisers for infringement. In 1987, a court granted summary judgment to the artist Saul Steinberg, who claimed that a poster for the film Moscow on the Hudson copied his New Yorker cover View of the World From 9th Avenue.

In May 2007, a French judge ordered the fashion designer John Galliano to pay 200,000 to the photographer William Klein in a dispute over a series of magazine ads that mimicked Klein's technique of painting bright strokes of colour on enlarged contact sheets.

Recently, Zaretsky was approached by the artist Spencer Tunick, who is known for his photographs of large installations of naked people in public places. Tunick was concerned about a TV commercial for Vaseline shown in Europe and the United States in 2007. The 60-second spot, called Sea of Skin, features large groups of naked people posed in artful configurations in various outdoor settings. They stand and sway in a forest, sit on a concrete rooftop, and bounce gently in a glacial lake.

"There was such a close resemblance to my work that it was uncanny," Tunick says. "When I saw the ad, I thought it was definitely inspired by my photographs and videos of installations." Was it? Not according to Kevin Roddy, the executive creative director at Bartle Bogle Hegarty in New York, who developed the commercial for Vaseline's parent company, Unilever. "I'm familiar with Spencer's work," Roddy says, "but I can't say that was an influence at all. Spencer is about masses of people and nudity. We're about representing the functionality of skin." Tunick says he has not decided whether to pursue legal action.

In some cases, artists who see variations on their own images may be victims of their own popular success. In the late 1990s, there were several disputes in which British art stars accused advertisers of pilfering their ideas. The conflicts arose around the time the so-called Young British Artists were featured in Sensation, a 1997 London exhibition of contemporary art from the collection of Charles Saatchi that later traveled to Berlin and New York.

In 1998, one of those artists, Gillian Wearing, complained that a Volkswagen commercial featuring people holding handwritten signs had copied the style and idea of her series of photographs titled "Signs that say what you want them to say and not signs that say what someone else wants you to say" (1992-93).

For her series, Wearing photographed people on the street holding paper signs on which they had written brief statements describing their feelings or states of mind. In one, a smirking young man in a suit holds a sign that reads "I'm desperate." The VW ad includes a shot of a tough-looking security guard who holds a sign bearing the word "sensitive." Wearing did not pursue legal action.

The following year, Damien Hirst threatened to sue British Airways over a billboard for its low-cost subsidiary Go that featured a grid of coloured dots. Hirst claimed that the design was based on his dot paintings. At the time, a spokesman for Hirst told The Independent that he had discussed licensing his dot paintings to British Airways, but that the deal had fallen through.

Advertisers have traditionally tapped into the cultural cachet of fine art by commissioning works for hire. From 1950 to 1975, a Chicago company, the Container Corporation of America, commissioned dozens of artists – including Fernand Leger, Ren Magritte and Willem de Kooning – to create paintings that were reproduced in print ads that ran in upscale magazines.

In 1985, Absolut vodka began its magazine ad campaign featuring variations on the distinctive shape of its bottle, executed by hundreds of contemporary artists, among them Andy Warhol, Keith Haring and Lisa Yuskavage.

But plenty of other artists have staunchly resisted agencies' requests to license their work. Tunick says he has been asked to work on campaigns for Dove, Lipton and Microsoft, among others. "I think I get two e-mails a week from ad executives or publicists who want to use my work, and I always tell them I'm not an advertising photographer."

The Swiss artists Peter Fischli and David Weiss have turned down numerous requests from ad agencies interested in licensing their award-winning 30-minute short film, Der Lauf der Dinge (The Way Things Go). Produced in 1987, it follows a Rube Goldberg-style chain reaction in which everyday objects like string, balloons, buckets and tyres are propelled by means of fire, pouring liquids and gravity.

In 2003, Honda ran a two-minute ad, Cog, in which various parts of a car form a domino-like chain reaction that culminates when an Accord rolls down a ramp as a voice-over (read by Garrison Keillor) intones, "Isn't it great when things just work?" At the time Fischli told Creative Review magazine: "We've been getting a lot of mail saying, 'Oh, you've sold the idea to Honda.' We don't want people to think this. We made Der Lauf der Dinge for consumption as art."

In a strange twist, the Honda Cog ad, which was developed by Wieden & Kennedy, has inspired several parodies of its own, including commercials for BBC Radio and the British directory assistance service 118. The chain reaction of creative influence, imitation and homage was the focus of a panel discussion at the Tate Modern in London during a retrospective of Fischli and Weiss' work there in 2006.

In an age when sampling and appropriation have become widespread practices in contemporary art and in the culture at large, some find it paradoxical that artists are now guarding their own creations more vigilantly. Michael Lobel, a professor of 20th-century art who has written about Roy Lichtenstein and Richard Prince, says the easy availability of digital images on the web has helped foster this defensiveness.

"There's a broader consciousness among artists about owning their work and keeping tight control over its distribution," he says. "The more available images have become, the more of a countermovement there is to clamp down."

Lobel says that while he sympathises with artists who believe their work has been copied, they also need to recognise their own reliance on existing images. "Culture is about ongoing borrowing," he says. "It's about taking images, ideas and motifs and opening them up to new uses."

The cycle of influence goes round and round: ad agencies borrow from artists who borrow from advertising. Isn't it great when things just work?