Questions have been raised about the inclusion of personal data in Apple's new copyright free music tracks.

The Electronic Frontier Foundation, an independent consumer group that picked up reports from online technical news and blog site, Ars Technica, said the unencrypted embedded user information in these tracks raises privacy issues.

Apple recently started selling tracks free of digital rights management (DRM). DRM puts restrictions on digital songs or movies, dictating where and what devices the files are played on.

So far it is known that the information embedded in Apple's DRM-free tracks includes names and email addresses. But the EFF and sites such as Ars Technica are warning that other personal data could also be embedded and they were still investigating to see if this is the case.

The EFF said the public should consider if the songs that are being billed as free of so-called DRM technology are as free as they appear or if there still strings attached.

"The main questions we have are: why is it there, and what else is in the file? Additional information could well be harmless: iTunes tracks store album cover images, number of plays, and the day you downloaded the track. Apple needs to be clear about what is going on," said Danny O'Brien, a representative for the EFF.

There has been speculation from industry experts that the information could be used to track people who upload music to file-sharing sites. This could lead to people being sued by the music industry for breach of copyright laws.

But the data, such as emails, is easily accessible by simply hitting "Get Info" on a track in iTunes. This means email addresses which are also the account log-in could be spoofed.

O'Brien asked: "If someone fakes your email on a shared file, will you get into trouble?"

The EFF has called for an open discussion. So far no comment has been received from Apple about the purpose of keeping this information or if more personal data is also kept.