A system for controlling use and distribution of digital works. In the present invention, the owner of a digital work attaches usage rights to that work. Usage rights are granted by the "owner" of a digital work to "buyers" of the digital work. The usage rights define how a digital work may be used and...http://www.google.ca/patents/US5629980?utm_source=gb-gplus-sharePatent US5629980 - System for controlling the distribution and use of digital works
