With the increasing availability of digitally stored information and the development of new multimedia broadcasting services, security questions are becoming ever more urgent. The acceptance of new services depends on whether suitable techniques for the protection of the information providers' interests are available. One problem that has not yet found a solution is the question of how to realise copyright protection for digitally stored data. This paper gives an overview of the problem and current activities that are concerned with this issue, and then presents different levels of copyright protection mechanisms that form a hierarchical protection scheme. Finally, a copyright protection system for multimedia information, developed at the Fraunhofer Institute for Computer Graphics, is described.