When you buy music from the iTunes music store, the iTunes music store embeds your name and email address in the downloaded track. They do this whether or not the track is free of DRM. It's not clear why they are doing this, but they most certainly are. If this makes you nervous (and it should), there is a way to erase your personal information from tracks that you buy on iTunes -- there is an application called Privatunes that does just this. It runs on both Windows and Mac machines. If you want to protect your privacy, you'll want to run this on all the tracks you buy from the iTunes music store.