The Max Headroom broadcast incident was a television hijacking that occurred on November 22, 1987 in Chicago, Illinois.
The first intrusion happened during a local newscast. It depicted an unknown man wearing a Max Headroom (a British, computer generated TV host introduced in 1984) mask sitting before a sheet of metal that resembled the original show’s background, along with a steady buzzing noise and no discernible audio. The hijack lasted about 30 seconds before finally being cut off.
The second intrusion cut in during a showing of Doctor Who, although this video came with distorted audio. The unknown man proceeded into various random phrases and antics, including a cut of being spanked with a flyswatter. The broadcast cut off after about a minute and a half. The above video is a recording from that particular hijacking. Fortunately (or unfortunately, damn), many copies of the hijacking were available from people who had been taping Doctor Who.
The hijacker was never identified.
(Source: https://www.youtube.com/)