In a bid for survival Napster, on Friday, announced plans to block its users from accessing over one million digital-music files from its service.

The plan was announced by Napster attorney David Boies during a hearing with lawyers from the Recording Industry of America (RIAA).

Boies told the court: "We've had a group of people at Napster working night and day for two weeks trying to find a process to block these names. Sometime this weekend we will have completed the software implementation."

Boies described the software as a "screen between uploading and viewing what has been uploaded".

Invisible files When Napster users search through each other's music files they are actually looking at a file index stored on Napster's servers. While copyrighted songs may continue to be stored on users' hard drives, the screen proposed by Napster will prevent those songs from showing up on its indexes, meaning other users won't be able to download them.

Judge Marilyn Hall Patel called Friday's hearing to gather information that will help her rewrite a ruling issued last July that would have shut Napster down for wide scale violation of music copyrights. The appeals court agreed that Napster fostered copyright violations, but postponed final judgement on the grounds that Patel's judgment was too broad.

Napster's move will probably have no effect on Judge Patel's ruling, said attorney Leonard Rubin, head of intellectual property at Gordon & Glickson. He added: "I don't think it will affect one word of the primary injunction."

Blocking files At the hearing, disagreements between the lawyers for the two parties focused on the question of which side should have to take the first step in blocking copyrighted material from the service.

Boies said: "If the RIAA gives us the name of the file they want blocked, we'll police our system."

The approach favoured by the RIAA is quite different, however. When Boies suggested that the RIAA should be required to show Napster that each copyrighted file exists on the system, Russ Frackman, attorney for the RIAA argued against such a plan.

"That's not an injunction, that's trying to solve the problem after the horse has already left the barn," he said.

Boies appeared to be making an attempt to satisfy the RIAA with the screening system. "This screen, when it goes up this weekend, will be updated all the time," he said.

New music Other arguments touched on how newly released music will be dealt with. The RIAA would like Napster to add the names of newly recorded music to its file index before those songs are actually released. Napster wanted to handle things differently.

"Once they show us that a user is offering a (copyrighted) file, we're going to block whatever name they give us," Boies said of the recording industry.

The surest way for Judge Patel to proceed would be to ask the record labels to provide a list of all their copyrighted songs, and then have Napster block everything on that list, according to Rubin.

Under US law, in almost all situations the burden lies initially with the copyright owner to provide notice of a violation, and then shifts to the service provider who must remove the offending material.

Napster CEO Hank Barry voiced his displeasure following the proceedings. The RIAA is seeking too powerful of an injunction such that "the only way we can follow it is to completely shut down".