A security firm is using metal detectors and night-screen goggles to search cinema-goers seeing Disney's latest animated movie release, Finding Nemo.
The film's characters live underwater
Disney wants to stop people from illegally taping its underwater adventure, made by Pixar Films, famed for Toy Story and Monsters, Inc.
Blockbuster hit The Matrix Reloaded has already been pirated, with copies available to download online less than two weeks after the film went on release around the world.
A high-quality copy of the film was being downloaded by hundreds of people each day via a website until it was taken down on Tuesday.
"Most people think the extra security is just for terrorism reasons," said security guard Robert Kendrick at a recent screening for the film in Oregon, US.
The use of metal detectors and night goggles is still a fairly new practice, having been most recently used in early screenings of X-Men 2 in May and more recently at Down With Love, starring Renee Zellweger and Ewan McGregor.
The orange fish, Marlin, is looking for his son Nemo
Security guards use the metal detectors to try to find digital cameras, and then monitor the audience with the night-goggles for 25-minute shifts, to see if there are any strong lights coming from a video recorder.
"These goggles magnify the light and make the image glow," Kendrick said.
Studios are very keen to prevent copies of their films hitting the black market, denting box office takings.
In April, a 33-year-old California man was arrested and charged with illegally videotaping films - if convicted, he faces up to 26 years in federal prison.
Warning on tickets
"It's estimated we lose between $3bn (£1.8bn) and $4bn (£2.4bn) a year to this problem despite strong anti-piracy actions by the movie industry," said Rich Taylor, a spokesman for the Motion Picture Association of America (MPAA).
The MPAA represents Hollywood's major studios including Disney and Fox.
Preview tickets for Finding Nemo have a warning about illegal recording printed on them.
Cinema-goers are told that if video equipment is found on them they will be denied admission, and if it is used it will be confiscated.
To make Finding Nemo, Pixar's animators worked with new technology to create a believable underwater kingdom.
It focuses on a fish called Marlin who is looking for his lost son, Nemo, off the coast of Australia.
Pixar and Disney topped the weekend box office charts in North America for the debut of each of their four co-productions, including Toy Story and Monsters, Inc.