SAN JOSE, Calif. - Apple Inc.'s recent rollout of songs without copy protection software at its iTunes Store has given consumers new flexibility, but questions have emerged over the company's inclusion of personal data in purchased music tracks.

Are the songs that are being billed as free of so-called digital rights management technology really "DRM-free" or are there still strings attached?

The Electronic Frontier Foundation, a consumer watchdog group, said the embedded user information in the purchased track raises privacy issues.

Apple declined to comment.

The trendsetting Cupertino-based company has always embedded user information -- a user name and e-mail -- into its copy-protected tracks. But until the market-leading iTunes Store began offering DRM-free music last week, no one raised much of a ruckus.

DRM technology puts a sort of software lock on digital songs or movies, dictating where and how the content can be played and distributed. With DRM-free content, some songs purchased from iTunes now work directly on portable players other than Apple's iPod, including Microsoft Corp.'s Zune.

Though piracy of digital music over the Internet remains unabated even with the growth of legitimate online retailers like iTunes, Apple's debut of DRM-free songs could tempt some of its users to share their purchased tracks with others online.

Technology blogs Ars Technica and The Unofficial Apple Weblog were among the first to reveal that personal data remained in the unrestricted iTunes tracks. Their reports last week prompted speculation that the data could be used to trace copies uploaded to online file-sharing networks back to the people who originally purchased the tracks, opening those users to music industry copyright lawsuits.

The Recording Industry Association of America, whose piracy lawsuits have ensnared organized outfits as well as individual grandmothers and youths, declined to comment. EMI Group PLC, the major record label behind Apple's inaugural batch of DRM-free songs, also declined to comment.

"DRM prevented us from playing the music we have purchased on all of our devices. We asked that this be removed and we got what we were looking for," said Erica Sadun, a prolific technology blogger on TUAW.com and author who conducted her own tests of Apple's embedded identification tags.

"But I'm on the fence in terms of the privacy issues," she said in an interview. "Consumers should always know what they're getting into."

The Electronic Frontier Foundation, which also analyzed the DRM-free song files on iTunes, said it did not want to jump to any conclusions on Apple's reasons for embedding the personal data.

Besides, users can remove their identifying data from the files simply by burning the tracks to a CD and then ripping the songs back to their computer in the MP3 format, said Fred Von Lohmann, an attorney with the San Francisco-based group.

Still, the group takes issue with the fact that the personal information stored in these type of song files is not encrypted. If someone were to lose their iPod or have their laptop stolen, for example, anyone using simple software tools could access the personal data in the songs, von Lohmann suggested.

"It just seems careless and unwise for somebody like Apple to start planting this kind of personal information without protection in the files," von Lohmann said. "It's not as bad as leaking your credit card number or your Social Security number, but it's still a pretty careless security leak."

Michael Gartenberg, an analyst at JupiterResearch, said he does not think Apple planned to use the personal data as a secretive tracking tool.

"I think it's more of a way of retaining a proof of purchase," he said, adding how the identifying tags on copy-protected tracks likely facilitated Apple's ability to approve user upgrades to previous song purchases.

"'DRM-free' means I'm not restricted from putting the songs on other devices anymore, but it doesn't give users a license for piracy," he said.

Ultimately, whether it's intentional or just an inadvertent deterrent for the illegal sharing of digital tunes, Gartenberg predicts other major online music retailers will similarly embed user tags once they, too, start to introduce DRM-free songs.

"I think everyone is going to have to do this as some way for tracking purchases," he said.

Sadun agreed.

"It's a brilliant compromise," she said, "between the forces of the music industry which have been too heavy handed and the forces of consumers who perhaps have pulled too far toward information freedom."

Online music retailer eMusic.com, which sells songs in the unrestricted MP3 format mostly from independent labels, says it keeps of a record of user purchases on its own computer servers but doesn't place any kind of user data in any of its tracks sold.

Apple should be more upfront about its purpose for the embedded information, said David Pakman, eMusic's chief executive. "You should tell customers what you're doing with it before they spend money with you," he said.