No charges were announced, but agents seized computers, software, and computer-related equipment in the searches" at five residences and one Internet service provider in Texas, New York, and Wisconsin, the Justice Department said in a statement.

"Today's enforcement action is the latest step in our ongoing effort to combat piracy occurring on the Internet," said Assistant Attorney General Christopher Wray.

"This is the first federal law enforcement action against criminal copyright infringement using peer-to-peer networks and shows that we are committed to combating piracy, regardless of the medium used to commit these illegal acts."

The raids were part of Operation Digital Gridlock, a joint investigation of the FBI and other divisions of the Justice Department.

The target was a group known as The Underground Network that engaged in massive sharing of digital content including films and music.

"These networks required users to share a minimum of one to 100 gigabytes of computer files with other users on the network," the Justice Department said.

"Upon becoming a member of one of these peer-to-peer networks, each user could then download shared files from the hard drives of all other members on the network."

Officials said the effort was part of a crackdown on piracy that costs an estimated 19 billion dollars to US producers of movies, software, games, and music.

Anyone charged under US law in the case could face five years imprisonment and fines of 250,000 dollars for each count, as well as forfeiture of computer equipment used to make pirated materials.

YahooTech