What’s the point of buying WMA files? As pointed out by Cory Doctorow, Microsoft’s DRM is a format fraught with problems. It’s not even an issue of own versus rent; the mischief this scheme can perform on a system is ridiculous.
Worse still, at least for Amazon, it doesn’t work to protect files. Witness the current war between WMA DRM and the rogue FairUse4WM application. The cracking tool not only unlocks content for playback, but also strips rental data:
What I meant to imply is that if you’re Amazon or any other company relying on a technology that others seemed determined to break and that’s core to your business model, that is definitely cause for concern. Not just to avoid piracy of downloaded content, but also to manage rental expiration (another “function” of DRM and a clear demonstration of the nearly arbitrary remote control that such a technology can give to others over your system)
It’s one thing to insert a flag that renders the files inoperable after a certain point in time, quite another to open up a system to willy-nilly file deletion. I’m starting to understand the vehemence of certain DRM-haters.