1. A method for recognizing manipulation attempts at a self-service terminal having a control panel with elements arranged therein that are provided for users of the self-service terminal, wherein a camera is directed towards at least one of the elements and wherein the image data generated by the camera are evaluated by a data processing unit, wherein at least one edge image is created by means of edge detection from the image data generated by the camera and in that the edge image is evaluated by means of a reference edge image, wherein at least one of the camera or the data processing unit is deactivated during operation of the self- service terminal, wherein to evaluate the at least one edge image, edge image data, which represent the edge image, are linked logically with reference edge image data, which represent the reference edge image, to form first results image data, which represent a first results image.