Digital rights management (DRM) is a class of controversial access control technologies that are used by hardware manufacturers, publishers, copyright holders, and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that are not desired or intended by the content provider. DRM also includes specific instances of digital works or devices. Companies such as Amazon, AT&T, AOL, Apple Inc.
For an early view of digital rights management and XrML see:
XrML and Emerging Models of Content Development and Distribution