Abstract: A system and corresponding method for providing security against unwanted viewing of information being displayed on a video terminal of a computer workstation, the computer workstation including an input device such as a keyboard, the system including: a camera, responsive to the presence of any user of the computer workstation, the camera for providing from time to time a camera image suitable for indicating whether at the time a user is viewing the video terminal; a guard module, hosted by the workstation, responsive to the camera image, and further responsive to a notice of activity on an input device, the notice provided by the operating system of the workstation, for providing in pre-determined cases a command to the operating system to open a covering window and to display on the video terminal the covering window as the active window, the covering window of sufficient size to cover substantially all of the information bearing regions being displayed on the video terminal; wherein the pre-determined cas