In “Look! Four Horsemen!” I wrote about how iTunes Plus tracks contain your e‑mail address even though they are DRM-free. The same day, CNet published an article called “iTunes Plus: Everything you need to know” in which they state:
Be warned: your account information is stored in every file
Although iTunes Plus files feature no copy protection, files downloaded still contain the e‑mail address you have registered with iTunes. So although files can physically be shared with, and played by, friends and family, any of your purchases that end up on file-sharing networks, for example, can be traced back to you.
This shouldn’t come as a huge surprise, really. If you right-click a track and choose Get Info within iTunes, the purchaser’s e‑mail address is listed as an attribute of the song, and that information has to come from somewhere. This could raise privacy concerns for some, but I don’t have significant problems with it, really. I wanted DRM-free downloads so I could use them as I choose, not so I could upload them to a file sharing site.
If my computer were stolen, I’d prefer the music not be traceable back to me because I will have no control over what the thief does with it, but this is not going to prevent me from buying music.