Apple's DRM-free EMI music includes a trap for the pirates.
When you purchase DRM-free music from the iTunes Store information about you is tagged onto it. Look for file information and you will see your name and your email address.
Should this music end up on a file sharing service it will lead the music companies straight to the culprits.
The fact that music can be protected in this way begs the question, why was the current FairPlay DRM ever necessary?
Read more about Apple's DRM-free trap here.