Today was the first (and hopefully the last) time in my life that I used iTunes, and I was reminded yet again how much I loathe DRM. This past summer, I attended a Dave Matthews concert, and as such, I was given a coupon to download a "best of the tour" album from iTunes. The coupon expires on December 31, so I logged on to iTunes on my parents' computer, entered in the code, and received 8 files encoded in a DRM-encumbered m4p format.
Making these files (which are legitimately mine) play on Linux is going to be a pain, if Googling for "m4p linux" is any indication.
I reaffirm my oath to never give a penny of my money to Apple under any circumstances.