By Ted Bridis
The Associated Press

WASHINGTON - The recording industry is providing its most detailed glimpse into some of the detective-style techniques it has employed as part of its secretive campaign against online music swappers.

The disclosures were included in court papers filed against a Brooklyn woman fighting efforts to identify her for allegedly sharing almost 1,000 songs over the Internet.

The recording industry disputed her defense that songs on her family's computer were from compact discs she had legally purchased.

According to the documents, the Recording Industry Association of America examined song files on the woman's computer and traced their digital fingerprints back to the former Napster file-sharing service, which shut down in 2001 after a court ruled it violated copyright laws.

The RIAA, the trade group for the largest record labels, said it also found other evidence inside the woman's music files suggesting the songs were recorded by other people and distributed across the Internet.

Comparing the Brooklyn woman to a shoplifter, the association told U.S. Magistrate John Facciola that she was "not an innocent or accidental infringer" and described her lawyer's claims otherwise as "shockingly misleading."

The woman's lawyer, Daniel N. Ballard, of Sacramento, Calif., said the music industry's latest argument was "merely a smokescreen to divert attention" from the related issue of whether her Internet provider, Verizon Internet Services Inc., must turn over her identity under a copyright subpoena.

"You cannot bypass people's constitutional rights to privacy, due process and anonymous association to identify an alleged infringer," Ballard said.

Ballard has asked the court to delay any ruling for two weeks while he prepares his arguments, and he noted that his client - identified only as "nycfashiongirl" - has already removed the file-sharing software from her computer.

The recording industry association accused "nycfashiongirl" of offering more than 900 songs by the Rolling Stones, U2, Michael Jackson and others for illegal download, along with 200 other computer files that included at least one full-length movie, Pretty Woman.

The court papers describe in unprecedented detail some sophisticated forensic techniques used by its investigators.

For example, the industry disclosed its use of a library of digital fingerprints, called "hashes," that it said can uniquely identify MP3 music files that had been traded on the Napster service as far back as May 2000.

Examining hashes is commonly used by the FBI and other investigators in hacker cases.

By comparing the fingerprints of music files on a person's computer against its library, the association believes it can determine in some cases whether someone recorded a song from a legally purchased CD or downloaded it from someone else over the Internet.

Copyright lawyers said it remains unresolved whether consumers can legally download copies of songs on a CD they purchased rather than making digital copies themselves. But finding MP3 music files that precisely match copies that have been traded online could be evidence a person participated in file-sharing services.

"The source for nycfashiongirl's sound recordings was not her own personal CDs," the association's lawyers wrote.

The recording industry also disclosed that it is examining so-called "metadata" tags, hidden snippets of information embedded within many MP3 music files. In this case, lawyers wrote, they found evidence that others had recorded the music files and that some songs had been downloaded from known pirate Web sites.

The industry has won approval for more than 1,300 subpoenas compelling Internet providers to identify computer users suspected of illegally sharing music files on the Internet.

Sen. Norm Coleman, R-Minn., chairman of the Senate Governmental Affairs' permanent subcommittee on investigations, has promised hearings on the industry's use of copyright subpoenas to track downloaders.

The association has said it expects to file at least several hundred lawsuits seeking financial damages as early as next month.

U.S. copyright laws allow for damages of $750 to $150,000 for each song offered illegally on a person's computer, but the group has said it would be open to settlement proposals from defendants.

The campaign comes just weeks after U.S. appeals court rulings that require Internet providers to readily identify subscribers suspected of illegally sharing music and movie files.