Only days after internet-based music streaming services that capitalise on Apple Computer's iTunes technology appeared, many of the web sites that hosted them have removed the feature, citing concerns about piracy.
Apple iTunes Music Store is the company's wildly popular online music purchase site, which launched on 29 April and has already had more than two million downloads, even though the service is only available to the small number of Mac users.
The online service allows users to download songs from a library of more than 200,000 songs for 99 cents each using a special software client.
Within days of its release, however, programmers outside of the company found ways to harness an iTunes client feature called Rendezvous that enables Macintosh users to share downloaded songs with other machines on a Lan or over the internet.
Sites such as www.spymac.com, shareiTunes.com and www.itunesdb.com began offering a music streaming service that allowed registered users to browse and search the collections of other iTunes users, then listen to those songs streamed over the internet.
The sites relied on the work of programmers who had deciphered a protocol that iTunes uses to stream music, according to David Benesch, a software developer.
Benesch cracked the protocol, named DAAP, as a "weekend project", figuring out how to pull information out of a command in the protocol that is used to transmit the name of the artist and song.
Benesch provided his code to Spymac.com after the Apple enthusiast site expressed an interest in using it as the basis for an online iTunes stream sharing service.
But while Benesch's code enabled the iTunes users to display their song catalogues online through Spymac's music site, other developers had worked out how to capture the actual music stream from iTunes.
Within days of the web-based iTunes databases appearing, tools with names like "iLeech" appeared that enabled users not just to listen to songs streamed from other iTunes users music database, but to copy them.
The tools turned the services into the foundation for an online file-swapping service, he said.
And while listening quality varies for songs streamed over the internet, especially when the user hosting the song has a low bandwidth Internet connection, songs ripped from streamed MP3 or AAC (Advanced Audio Coding) files would be identical in quality to the originals, Benesch said.
In response to the growing concern about stream ripping tools, at least two iTunes streaming sites have been shut down, including Spymac's music site and iTunesdb.com.
Spymac.com said that the decision to remove the service was necessary after efforts to thwart stream ripping by hiding the IP addresses of shared streams were quickly sidestepped by determined programmers.
The iTunesdb.com site contained a similar statement from Rob Lockstone, the site's owner.
Lockstone denied that the decision to shut down the service was the result of pressure from Apple or the music industry, but did cite concern about the legality of the services as a contributing factor to take iTunesdb.com offline after less than a week.