Hollywood fears the growth of online piracy

The adverts on US television and in cinemas feature makeup artists, set painters and other crafts people who explain that piracy deprives them of a living.

The Motion Picture Association of America (MPAA) has also developed a curriculum on copyright for use in classrooms.

The film industry is hoping to avoid the debilitating effects of online piracy which has hit the record industry in the last few years.

The campaign asks people to "put an end to piracy".

Terminator 3 has been pirated online Watch the campaign trailers

"I don't expect anyone to have sympathy for me or for other executives," said Peter Chernin, president and chief operating officer of News Corp, the parent firm of 20th Century Fox, which made the adverts.

"What we are endeavouring to do is both communicate that it's wrong and also communicate that there are human stakes and that those stakes are not just millionaires making less millions."

Online movie piracy, while still a relatively small part of overall film piracy, is beginning to grow as internet connections become faster.

Many blockbusters can be found pirated online, sometimes days before the films have even been released in cinemas.

Experimenting

Film studios believe they still have a few years before internet connections become fast enough to threaten them.

Studios are experimenting with new business models, including making films available legitimately online through services such as Movielink.

It's in the long term interest of people to understand there is no free lunch Jack Valenti, MPAA

"We're not sitting on our hands like the music business did," Mr Chernin said.

"It may just be that consumers aren't quite ready yet to turn to the internet for movies," said Fred von Lohmann, a lawyer for the Electronic Frontier Foundation.

"But when they are, the answer will be to offer them a compelling legitimate alternative, not telling them to behave themselves," he added.

The 30-second television advert will have its first run Thursday night on all the main TV networks.

The first of several trailers will begin running Friday in most major cinema chains around the US.

The first trailer features David Goldstein, a set painter who says that piracy hurts him more than film industry executives.

Each ad ends with the tag line: "Movies. They're worth it."

The campaign will also include a website that outlines the implications of illegal downloading as well as the legal and practical consequences.

"Taking something that doesn't belong to you is wrong," said Jack Valenti, president of the MPAA.