DRM (or digital rights management) has been around for a few years now and started out as a series of simple technologies designed to prevent software users from making illegal copies or tampering with software after purchase. This system of copy protection can be thought of as a simple extension and reaffirmation of the Digital Millennium Copyright Act (DMCA), which imposes criminal penalties on users who attempt to overcome anti-copy technologies.
Recently however, DRM systems have been expanded to require that a user's incoming and outgoing data be monitored when using their purchased software, and some programs require users to be hooked into an account via internet in order to access their DRM protected content. Some newer DRM systems are actually software interpreters which access information on external servers and retrieve and interpret it for the user, then delete it from memory when done. Despite the fact that users may have purchased an ebook, music, or software on this type of DRM system, the user never actually possesses a real copy of the item.
The gaming scene comes to mind when digital rights management is mentioned. Outlets such as Steam and Origin allow gamers to purchase titles over the internet and download them. Once downloaded, the software is tied to the user's specific steam/origin account, and if that information were lost, the software would be rendered inaccessible to the user.
Modern tablet computers utilize online 'play' stores to allow the tablet user to download and view ebooks, videos, music and other software. For example, Google makes use of DRM software on their Android platform by allowing users to purchase ebooks on the Google Play store, but once purchased, the ebook is never truly transferred to the user's tablet. Instead, users receive a 'shadow' copy which can be erased if need be by the tablet's operating system or by Google themselves.
The methods used in creating digital rights management software definitely do a fantastic job of protecting the copyrights of the creators of the software content, and certainly allow them to keep track of how many users have purchased their content, as well as how they use it.
But the rights of the customer are pandered to much less than the creator of the content. In fact, if Google were to shut down their play store, all DRM locked purchases made would be worthless. If a user attempted to recover his content after such a collapse, he would effectively be considered a criminal under the DMCA simply for attempting to recover the software he purchased.