A three-judge panel of the Ninth Circuit Court of Appeals today issued a 58-page opinion in which it held that the popular peer-to-peer song-swapping service Napster must stop enabling users to access copyrighted material served by Napster users. The Appeals Court action follows an injunction against Napster originally issued 26-Jul-00 by Judge Marylin Patel, which barred Napster from “causing, assisting, facilitating, copying, or otherwise distributing all copyrighted songs or musical compositions.” Two judges on the Appeals Court issued a temporary stay against that injunction almost immediately, pending arguments from both Napster and the Recording Industry Association of America (RIAA), who is suing Napster for promoting piracy and copyright infringement. (See "Judge Presses Napster’s Buttons" in TidBITS 541.) The Appeals Court decision permits Napster to remain operating until Judge Patel modifies her original "overbroad" injunction. However, the decision also requires Napster to prevent users from accessing content that would violate copyright and rules Napster had both actual and constructive knowledge of direct copyright infringement. Napster could be held liable for failing to monitor its system for copyright violations, as well as for contributory copyright infringement. Napster is expected to appeal the decision to the full Appeals Court, or even to the U.S. Supreme Court; the full text of the decision is available from FindLaw.com.