Here's a story from the East German era... In East Germany it was illegal to watch Western TV, but it was possible because the West deliberately had strong transmitters aimed at the East. There was a tradition that the evening news began by showing a big clock ticking for a few seconds with a chime on the hour that started the broadcast. People used to set their wall clocks and watches to this. On the West's channel this clock was round, on the East's it was square. So in East Germany they asked children in school to draw the clock they saw on television, and if it was the wrong shape their family would get a visit from the Stasi.