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 nearly 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. The RIAA's latest 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 computer investigators in hacker cases. By comparing the fingerprints of music files on a person's computer against its library, the RIAA 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 RIAA'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. Source and full story: CNN