Pr Edward Felten dans 'A Perfectly Compatible Form of Incompatibility'
The whole point of DRM technology is to prevent people from moving music usefully from point A to point B, at least sometimes. To make DRM work, you have to ensure that not just anybody can build a music player — otherwise people will build players that don't obey the DRM restrictions you want to connect to the content. DRM, in other words, strives to create incompatibility between the approved devices and uses, and the unapproved ones. Incompatibility isn't an unfortunate side-effect of deficient DRM systems — it's the goal of DRM. - (Source)