Patent ID: 7631806

Claim:
A system for detecting an unauthorized user of a valid data carrier including at least one access control device with a reading device for data carriers upon which identification details are stored for assigned authorized access, and a database in which a photograph of the user of the data carrier, together with the identification details on the data carrier, is stored, wherein at least one camera located at an access control device takes digitized photographs of the users of the access control device that are stored, together with the identification details, in a database, at least one terminal having a screen, communicating with the database, operable by an official so that the identification details on the data carrier are retrievable, and to which the stored photograph of the user of the data carrier taken by the camera during access via the access control device, together with the corresponding identification details, is transmissible for visual comparison with the user of the data carrier being checked, wherein the system permits an unauthorized user to pass through the access control device at least once before a visual comparison to determine if the data carrier is being utilized by the proper user.