Abstract: According to one aspect, the subject matter described herein includes a method for secure content watermarking. The method includes generating a watermark that encodes information as a set of visual elements; receiving content that represents a graphical workspace to be displayed to a user; creating watermarked content by combining an image of the received content with at least one copy of the watermark sufficient to fill the area of the image; and displaying the watermarked content to the user via a display device having a display area. Should the user take a screenshot or take a picture of some or all of the watermarked content, the picture so acquired will contain watermark information that can be used to identify the session from which the picture or screenshot was taken.