A security researcher warned iTunes customers Thursday that Apple encodes the buyer's account name and e-mail address in the new DRM-free tracks that debuted Wednesday.
The data added to noncopy protected files purchased on iTunes can be viewed after the track is played by pulling up its File Info dialog in Mac OS X, said "mordaxus," one of the regulars who writes on the security blog Emergent Chaos.
"They [Apple] aren't the only one to watermark the files," said mordaxus, who pointed out that eMusic does something similar.
All iTunes files include the name on the buyer's account and the associated e-mail address -- not just the new DRM-free tunes. But their inclusion on noncopy protected songs is significant, mordaxus said, because some people might be tempted to share bought music on a peer-to-peer (P2P) network.
"If you're going to put music files up a P2P network, you cannot be paranoid. They are out to get you," said mordaxus. "It would be folly to take any music you bought from any service and serve it up."
The Unofficial Apple Weblog posted a three-step set of instructions on how Mac OS X users can use Terminal to dig into an iTunes Plus file.
Apple did not returns calls asking why iTunes tracks, whether protected by DRM or not, contain buyer data.