Digital rights management(DRM)technologies attempt to control or prevent access to or copying of digital media, which can otherwise be copied with very little cost or effort. Copyright holders, content producers, or other financially or artistically interested parties have historically objected to copying technologies, even before the advent of digital media. Examples have included player piano rolls early in the 20th century, audio tape recording, and video tape recording (e.g. the "Betamax case" in the U.S.). Digital media has only increased these concerns. While analog media inevitably loses quality with each copy generation, and in some cases even during normal use, digital media files may be copied an unlimited number of times with no degradation in the quality of subsequent copies. Digital Audio Tape, thought by many observers of the time to be a probable replacement for the audio cassette, was a market failure in part due to opposition to it on grounds of unauthorized copying potential.

Many online music stores employ DRM to restrict usage of music purchased and downloaded online. There are many options for consumers buying digital music over the internet, in terms of both stores and purchase options. Two examples of music stores and their functionality follow:

• The iTunes Store, run by Apple Inc., allows users to purchase a track online for $.99 US. The tracks purchased use Apple's FairPlay DRM system.
• Napster music store, which offers a subscription-based approach to DRM alongside permanent purchases. Users of the subscription service can download and stream an unlimited amount of music encoded to Windows Media Audio (WMA) while subscribed to the service. But as soon as the user misses a payment, the service renders all of the downloaded music unusable. Napster also charges users who wish to use the music on their portable device an additional $5 per month. Furthermore, Napster requires users to pay an additional $0.99 per track to burn it to CD or listen to it after the subscription expires. Songs bought through Napster can be played on players carrying the Microsoft PlaysForSure logo (which, notably, do not include iPods or even Microsoft's own Zune).
• Wal-Mart Music Downloads, another online music download store, also uses DRM. It charges $0.88 per track for all non-sale downloads. All Wal-Mart Music Downloads are able to be played on any Windows PlaysForSure marked product. However, this music will not play on the Zune. The music does play on the SanDisk's Sansa mp3 player, for example, but must be copied to the player's internal memory. It can not be played through the player's Micro SD card slot, which is a problem that many users of the mp3 player experience.