The Naval Academy's seizure of nearly 100 student computers last week appears to be the most drastic response by an American college or university to concerns that campuses are becoming hothouses for illegal downloads of copyrighted music and movies, experts said yesterday.

Details about the seizures remain hazy, with officials at the military college confirming little beyond the existence of an internal investigation.

But sources said that academy officials ordered the school's 4,000 students to turn on their dorm-room computers and log on to the school's network before leaving for class Thursday. When students returned, almost 100 found their computers gone. Notes were left behind informing them of the investigation, said an alumnus who spoke with a half-dozen midshipmen about the issue.

"Half the Mids in the brigade are scared to death," said the alumnus, who spoke on condition of anonymity for fear of jeopardizing a relationship with the academy. "No one knows exactly what's going to happen."

Cmdr. Bill Spann, academy spokesman, said that midshipmen found to have downloaded copyrighted material could face penalties ranging from a loss of liberty to a court martial and even expulsion.

Those penalties struck some education experts as particularly harsh. But others said the academy's stance could prod other colleges to go tougher on students who go online to download pirated copies of their favorite Eminem tune or the latest Avril Lavigne video.

"This has certainly gotten people's attention across the country," said Sheldon Steinbach, general counsel for the American Council on Education, a Washington higher-education group.

Privacy advocates, however, warned that the academy's sting could set a harmful precedent by casting college administrators in the role of thought police and making students fearful of pursuing controversial strands of academic research.

"To seize their entire computer is a drastic step," said Chris Hoofnagle, legislative counsel for the Electronic Privacy Information Center, a research and advocacy group. "This is a type of step you use against mob bosses."

For years, entertainment industry groups troubled by slumping sales of videos and recorded music have pointed a finger at campuses. Colleges, with their high-speed Internet connections and students raised on lightning-fast Web access to popular culture, have drawn stern letters from trade groups for the recording and motion picture industry.

College officials have had their own reasons to worry. The torrent of data that make up digital music files, known as MP3s, are slowing down university computer networks and hindering legitimate uses of the Internet.

At some colleges, up to 75 percent of a campus's Internet bandwidth is consumed by student file-swapping.

But the vast majority of colleges have responded with restraint, hoping to restrict improper use of their networks without trampling on student privacy and free speech.

The academy's honor code regards lying, cheating or stealing as a betrayal of the school's highest principles. And so some outside experts believe that the school's new superintendent, Vice Adm. Richard Naughton, may want to hammer home the message that those principles apply in cyberspace as well.

The U.S. Military Academy at West Point, N.Y., and the U.S. Air Force Academy in Colorado use software that blocks access to file-swapping sites akin to the defunct Napster. West Point acknowledged disciplining scofflaws, but neither school has seized computers.

"I don't know what else we would gain from actually seizing the computer," said Maj. Kent P. Cassella, West Point spokesman.

The Recording Industry Association of America, at the forefront of the anti-piracy campaign, issued a statement yesterday distancing itself from the academy action: "We appreciate institutions that take intellectual property theft seriously. However, we do not dictate what ... enforcement policies should be and, in this ... instance, we do not know the facts."

Anita Sweger, president of a Naval Academy parents association in Pennsylvania and the mother of a senior not part of the probe, said she's worried that the academy went too far. Often isolated from the outside world by the demands of training, midshipmen use their computers as a link to life beyond the academy's walls, she said.

"On the one hand, I think it's a pretty severe penalty," she said. "By the same token, these kids are held to such a high standard that it's their duty not to do the wrong thing."

That said, she added, "I certainly hope they would have warned them first."