Abstract: A system for controlling the playing of rented compact discs on an end-user's compact disc player. The end-user obtains a validation disc on which is stored a control program and an expiry date. When the validation disc is inserted into the user's player, the player downloads the control program into its memory and runs the program. This causes the expiry date to be read from the disc and stored in the player's memory. Discs to be played on the player have stored thereon a second control program which is downloaded into the player's memory when they are inserted into the player. This second control program causes the player to check whether or not the current date, as maintained by the player, is later than the stored expiry date. If the current date is later, playing of the disc is prevented, whilst if it is earlier, playing of the disc is allowed.