If you ever needed more proof of why DRM is just a terrible set of technologies that do nothing but frustrate legit customers, the MSN Music store is a prime example. The doomed service was shut down over a year ago upon the launch of the Zune, forcing people to switch to a new service. That minor annoyance aside, the change was manageable because Microsoft kept alive their authorization server for the DRM-locked music files people had previously purchased. Thus, even if the customer purchased a new computer, they could unlock that music.
But that is about to change. Microsoft has announced that they will cease maintaining the key retrieval service by the end of August.
As a result, for all the music purchased on the MSN Music store it will become impossible to retrieve your keys. If the music is transferred to another device, it can never be unlocked again - at least not in a legal way - rendering that purchase a total loss to that person. For those that have libraries of music purchased through the MSN store, they will be locked in to that specific hardware for as long as they want to use those files.
Ultimately, this serves as a reminder of what DRM really is: A way for companies to control your use of their content. Rather than purchasing, you are renting.