The company on Thursday posted a notice on the service saying the step is necessary to comply with a federal court order, which requires it to block access to certain files identified by the record industry as copyrighted works. Nevertheless, Napster acknowledged that the measures could obstruct some songs that fall outside the scope of the injunction.
In addition, the judge overseeing the case on Thursday put off a request by the record industry to order stricter remedies against Napster, saying she first wanted to hear the report of a technical expert assigned to the case.
The company has been blocking songs from being traded on its service with only limited success since early March, when U.S. District Judge Marilyn Hall Patel ordered it to halt swaps of much copyrighted music. But the record industry has complained that these efforts have been largely fruitless. Faced with evidence of continued swapping, Patel called the filters "disgraceful" earlier this month.
The legal pressure has finally forced Napster to give ground in its filtering strategy, changing the way it is blocking music so that even many songs not identified by record companies as copyrighted are being screened out. As a result, the availability of music on the service this week has fallen steeply.
In a note to Napster users posted Thursday, the company apologized for its actions.
"We have recently enhanced (our) filters in an effort to screen out the wide range of variations in artist name and song title that result in noticed works continuing to appear on the Napster index," the company posted. "That, in turn, has unfortunately caused substantial additional 'overblocking,' the unintentional removal of otherwise authorized works, for which we apologize to our users and artists."
The company also reminded potential file swappers that intentional use of filter-evading tools such as NapCameBack or Pig-Latin encoders are now a violation of Napster's terms of service. People using these tools will be warned and ejected from the music-swapping network if they keep sharing files this way, the company said.
Napster users began complaining about overblocking Thursday, saying that even collections of "obscure, out of print" music were disappearing.
"It's time to euthanize this sorry, dying excuse for a file-sharing service," wrote a Napster user going by the initials "HTC" on the company's message boards. "I don't blame Shawn Fanning or any of the management trying to keep Napster alive, but it's time to face reality--with the flagrant overblocking currently in place, Napster is useless."
The change in Napster's service marks a significant capitulation in its attempts to keep operating even while under a court injunction.
Until a few weeks ago, the company had consistently argued in court that it was not required to add filters that would obstruct trading of songs that had been approved for distribution over Napster. This so-called overblocking would interfere with the service's legitimate uses, which were protected by previous court decisions, the company contended.
But in a court hearing early this month, attorneys for music publishers and record labels pointed out that this strategy left gaping holes in the filters. Nearly every instance of the thousands of songs supposedly blocked was still available through Napster's service, they told the court.
Although Patel did not explicitly order Napster to change its strategy, she said the company's efforts to date did not measure up to her expectations. Overriding its concerns about overblocking, she said it was up to the company to make sure that the copyrighted works were blocked, regardless of the consequences to the rest of the service.
"You created this monster," she said, deliberately echoing her words of last summer, when she issued an order that threatened to shut down the company. "You figure it out."
Napster isn't releasing details on how the new filters work, saying it doesn't want to give people a road map for evading them. But a representative confirmed that in some cases the company has started screening by single words--an artist's name or a song title, for example--instead of requiring both to trigger the block, as it had in the past.
Patel issued an opinion late Thursday that clarified what the record companies must give Napster to trigger filtering, but she put off much of the decision on whether the filters are working well enough.
The judge said that the record labels must hand Napster the names of individual files that are being traded on the service, a point that has sparked some contention. She also asked both sides to submit new testimony within two weeks on how much information could be given to Napster about new releases before those albums hit the shelves.
Patel said that no decision will be made on how well the filters are working, however, until a court-appointed technical mediator has a chance to dig into the technology involved. No date has been set for his final report.