The Max Headroom broadcast signal intrusion incident was a television signal hijacking in Chicago, Illinois, on the evening of November 22, 1987; it is an example of what is known in the television business as broadcast signal intrusion. The intruder was successful in interrupting two television stations within three hours. The first occurrence took place on WGN-TV's live telecast of The Nine O'Clock News. The station's signal was interrupted for about half a minute by a video of a person wearing a Max Headroom mask. There was no audio, only a buzzing noise. Later that night, during a broadcast of Doctor Who, PBS station WTTW's signal was hijacked using the same video that was broadcast during the WGN-TV hijack, this time with distorted audio. Neither the hijacker nor the accomplices have ever been found or identified.