The title track of the singer's upcoming album, "Music," apparently has been leaked onto the Web well in advance of its release date. And the singer is not amused.
"This music was stolen and was not intended for release for several months. It is still a work in progress," Madonna's manager, Caresse Norman, said in a statement. "Those sites that offered a download of Madonna's music are violating her rights as an artist."
Madonna's recording label, Warner Bros. Records, followed with a stiffer warning.
"Any site that posts or makes available our copyrighted material without our consent runs the risk of civil and criminal prosecution," the label said.
But in Napster's case, at least, the threat borders on redundancy.
Warner Bros. Records is already suing Napster for the more generic availability of all the label's music though the software's service. The label is part of the Recording Industry Association of America coalition that first launched legal action against Napster in December.
In that case, the industry is asking for damages that could mount into the billions of dollars.
Madonna joins a long list of major-label artists who have seen their work leak onto the Net in advance of release dates. Fellow luminaries such as Paul McCartney, U2, Metallica and Van Halen all have seen songs released online, often through radio stations that received advance copies for airplay.
Most recently, popular rapper Eminem joined fellow Napster foes Metallica and Dr. Dre in public condemnation of the service after his own newly released album quickly began being traded through the service.
However, the unauthorized version didn't prevent that album from selling more than 1.7 million copies in the first week of its release, jumping to the top of U.S. pop charts.
Metallica and Dr. Dre remain the only artists who have sued Napster on their own. No word was immediately available as to whether Madonna's management has threatened Napster specifically with her own similar lawsuit.
Many of the Napster users who have been caught in the crossfire between Metallica and the software company found themselves allowed back onto the service today.
Under federal copyright law, Metallica had to individually sue those users if they were to be kept off the service indefinitely, and to date, the band has not been willing to take that step.
People who were recently barred from Napster as a result of a similar action from Dr. Dre are in the middle of their own appeals process.