See How iTunes Embeds Email in DRM Free Tracks
So the iTunes store is almost completely DRM free and will be entirely DRM free by spring…great we can now use our DRM free music on any device we want without any stupid hang-ups.
This is all good and dandy as long as everything is legit…which of course it is, right?
iTunes Plus Files now make up the entire music store and every file stores your account info and email. Even though there is no copy protection, the downloads still contain the email you have when you registered with iTunes.
So while you can physically share files with friends, family, etc. it can still all be traced back to you.
If you want to see for yourself how iTunes is keeping tabs on you, CNet says it's easy:
"If you're interested in an easy way to check your own files, find an iTunes Plus file on your computer. Then choose to open it with a text editor (Windows Notepad works fine). It'll take a while to open and will appear to be full of nonsense text, but if you choose the 'Find' option and type in the email address you have registered with the iTunes Store, you'll find that your DRM-free music is not personal information-free."
Still it's VERY unlikely that someone would actually get in "trouble" from this and have the RIAA come knocking at their front door. After all this is not new as iTunes has been doing this since they started using the Plus Files.
Just remember that just because the music is now DRM free, piracy and using P2P networks will not be any easier (or harder!). Apple is watching you…
Source: iTunes Plus: Everything you need to know - Crave at CNET UK