1. A method for controlling the reception and use of video signals by a television receiver, comprising the steps of: (a) storing a reception code indicative of a program content which it is desired to prevent from displaying by a television receiver; (b) receiving a video signal; (c) extracting a program code from a select portion of the received video signal, wherein such program code is indicative of the video signal's program content by detecting a select sync pulse in the received video signal, measuring elapsed time from the occurrence of the detected sync pulse, wherein the program code of the video signal occurs in a fixed time relation to the sync pulse, and clocking a digital signal corresponding to the program code into a memory; and, (d) comparing the extracted program code with the stored reception code to ascertain whether the video signal's program content matches the program content indicated by the reception code and, if so, blocking further receipt of such video signals by the display of the television receiver.