AMSTERDAM, Netherlands (Reuters) -- Police in a dozen countries have seized computers and made arrests in a raid of groups that illegally copied more than $50 million worth of software, movies, music and video games, U.S. and Dutch authorities said Thursday.
Investigators across the globe conducted 90 searches in an effort to disrupt the sophisticated "warez" groups that are responsible for the vast majority of copyrighted material that is available illegally online.
The 22 groups distributed "Star Wars Episode III: Revenge of the Sith," Adobe Systems Inc.'s Photoshop software, and hundreds of other well-known titles that had been stripped of their copy protection, the U.S. Justice Department said.
Four people were arrested in the United States and three more in the Netherlands, authorities in those countries said.
More computers were seized in Australia, Israel, Germany, South Korea, Norway, France, Sweden, Denmark, Russia, Poland, Canada and Hungary, according to the Dutch Finance Ministry.
"We have shown that law enforcement can find and prosecute those who try to use the Internet to create piracy networks beyond the reach of law enforcement," U.S. Attorney General Alberto Gonzales said at a press conference.
Warez groups are responsible for 95 percent of the copyrighted material that ends up on Internet "peer-to-peer" networks, according to U.S. Customs and Immigration Enforcement.
Motivated by fun rather than profit, warez groups rely on industry insiders to steal movies, software and other works before they're released, then strip them of their copy protection and post them on secret server computers.
From there, the works spread quickly across the Internet and become available to millions through peer-to-peer networks like Kazaa, or are burned onto discs to be resold by unscrupulous retailers around the world.
U.S. officials broke up a warez ring called DrinkOrDie in 2001, and led an international effort in April 2004 that seized 200 computers.
"One may wonder whether or not this is simply scraping the tip of the iceberg, but we believe it is very, very important to show the community that we care very much about the protection of intellectual property rights," Gonzales said.
"We believe that actions such as this are going to have, we hope, a significant deterrent effect."
In many countries it is not illegal to download certain digital files such as music, but it is illegal to upload them and make them available to other computer users on the Internet.
Recording labels and movie studios sued thousands of people who distribute their material through peer-to-peer networks, and have sued several peer-to-peer software makers for copyright infringement.
On Monday, the U.S. Supreme Court ruled that peer-to-peer networks can be held liable if they encourage users to copy protected works.