The Wyoming incident might have been a hoax, however, there was a very real pirate broadcast that happened in Chicago, back in 1987.
The first occurrence happened during the sports segment of WGN-TV Channel 9’s nightly news. The broadcast was cut in during the rundown of the Chicago bears, Detroit lion’s game when some static broke and a man in a Max Headroom mask came on the screen. It was brief, and there was no audio but it did get people’s attention.
Later that night, the highjacker broke into a broadcast of Dr. Who on WTTW, a PBS affiliate. This time there was audio and it was much longer.
The highjackers were never caught and I tend to agree with Max when he states that he created a giant masterpiece. I’m not a fan of performance art, but the cynical tone of this cryptic manifesto was delightful.