Is there a successful DRM system for anything? Again, I think the DRM that remains unbroken is unbroken because there's no point in cracking it. MS's PlayReady protects music and movies, so there's no reason to crack it since you can just rip the DVD/CD instead.

I don't think the argument that their DRM is exposed to a lot more risk by presence on desktop Linux is legitimate. Someone can break it on Windows or Mac without much extra effort if they cared to break it.