The European Economic Community study covers the problems raised by new information systems of the 1980s and 1990s. The main findings demonstrate that the spreading use of computers with versatile networking facilities has led to the obsolescence of some of the established control systems. The logical security provided by operating systems and basic software is generally inadequate. The study stresses the need for better data protection in public systems as well as in the private sector. It also stresses the need for wider and more efficient use of available means for the physical protection of computer centers and media.