1. A method of operating upon a video stream, the method comprising the steps of: at a user processing system: receiving a segment of the video stream, the video stream including video information for representing sequential frames, the video information including video data used substantially only for rendering sequential frame images; receiving a request for an action corresponding to a spatial-temporal location of displayed images located within the segment of the video stream; automatically detecting features in a vicinity of the spatial-temporal region of the segment of the video stream, the step of automatically detecting the features within the segment of the video stream operating upon the video data that is used for rendering the sequential frame images; obtaining a representation map of various regions of the video stream based upon the detected features; computing an electronic signature based upon the request and the representation map; and using the electronic signature to initiate performance of the action.