When someone purchases a song on iTunes, one thing they may not realise is that iTunes embeds some account information into the song file, including the user's full name and account e-mail.  As a result, a song that gets leaked out can be potentially traced back to the owner.  However, as all iTunes music up until recently has been crippled with DRM, this has not been an issue, since no one would distribute a DRM crippled file knowing that it will only play on a limited number of authorised devices.

Now that iTunes has launched its DRM free iTunes Plus service, some consumers may assume that it is ok to pass a copy of their purchased music on to friends now that these will play without restriction.  However, as the songs carry the owner's account information, there is a high risk that if someone ends up sharing out the songs online, anti-piracy organisations can easily view this embedded information.  While it is not clear if there is any audio watermarking present, the information is embedded as plain text within each song.

However, one drawback with the plain text information is that it can be easily spoofed, which means that if a copyright iTunes track is discovered on a file sharing network, it would be difficult to tell if the embedded info has been spoofed.  The info would also be lost if the song is converted into MP3 or any other audio format.

Thanks to GristyMcFisty for letting us know about this news.