A court has ruled that the recording industry should be prevented from forcing Internet service providers to identify their subscribers on peer-to-peer networks.

The ruling on Friday found that the RIAA (Recording Industry Association of America) should not subpoena Internet providers for subscribers' personal information without going through court.

According to a report in Wired, lawyers could, in theory, argue that details about the 382 file traders who have been sued by the RIAA was "unjustly obtained" from ISPs and therefore should not be used.

Meagan Gray, an intellectual-property attorney in Washington, DC, told Wired: "The fruit of the poisonous tree is a concept in criminal law that says if the police did not have a valid reason to get a search warrant, anything discovered as result of that search warrant cannot be used in court.

"But there really is no equivalent concept in civil law," she added.

Wired concludes that: "The decision will make it harder for the recording industry to make new claims against file traders, but that won't help many of those who are already facing lawsuits and can't afford a costly legal fight".

Regarding the ruling, president of the RIAA Cary Sherman said: "This decision is inconsistent with both the views of Congress and the findings of the district court. It unfortunately means we can no longer notify illegal file-sharers before we file lawsuits against them to offer the opportunity to settle outside of litigation."