On November 22, 1987 in Chicago there was a disturbing case of 🅷🅰🅲🅺🅸🅽🅶 still unsolved on the frequencies of a television station. The authors were never discovered and the whole story has always remained shrouded in mystery.
I refer to the "𝓜𝓪𝔁 𝓗𝓮𝓪𝓭𝓻𝓸𝓸𝓶 𝓫𝓻𝓸𝓪𝓭𝓬𝓪𝓼𝓽 𝓼𝓲𝓰𝓷𝓪𝓵 𝓲𝓷𝓽𝓻𝓾𝓼𝓲𝓸𝓷 𝓲𝓷𝓬𝓲𝓭𝓮𝓷𝓽".
It was a Sunday evening and on Channel 9 (WGN-TV 9, a private American broadcaster from Chicago) they were broadcasting a news program: Nine 'or Clock News (WGN News at Nine). The presenter was Dan Roan and was commenting on the Chicago Bears' victory over the Detroit Lions (30-10).
Suddenly the transmission disappears and there is darkness for a few seconds. Immediately afterwards a disturbing-looking character appears: it is a Max Headroom mask with someone moving a sheet behind it. There is also a disturbing hum.
The intrusion lasts only 20 seconds. Once the intrusion is over, a frightened Dan Roan reappears and can only say, with a nervous smile: "Well, if you're wondering what happened ... you're not the only one!", Then tries to pick up where he left off, but without success: the dismay is so great. In those 20 seconds, the WGN engineers managed to break the hacker's signal by changing the transmission frequencies.

Later, after exactly 2 hours, an episode of Doctor Who (The Horror of the Fang Rock) was broadcast on Channel 11 (WTTW TV11, Chicago public broadcaster). Suddenly the show is interrupted by a disturbance and the character masked by Max Headroom appears again. This time the intrusion also has audio and lasts for 1 minute and 22 seconds. The audio is very distorted and disturbed by hum:
"That does it
He's a frickn 'nerd
Yeah, I think I'm better than Chuck Swirsky
Frick'n liberal
Oh, Jesus
Yeah
Catch the wave
Your love is fading
(incomprehensible words)
I still see the X
Oh my files!
Oh, I just made a giant masterpiece
for all of the greatest world newspaper nerds
My brother is wearing the other one
It's dirty
(Looks like it's got blood prints on it)
(I'm going to put my fine off)"
Then the shot changes: the person who wore the mask is turned from the back with his face out of the field and his butt outside, he holds the mask he has taken off with his left hand and there is another person at his side dressed as a woman with a paddle in her hand that spanks him.
"They are coming to get me
Bend over bitch
Don't do it, nooooo"

After that, the show resumes curiously with the phrase:
"As far as I can tell a massive electric shock. He must have died instantly"
Was everything calculated?
This second station did not have the possibility to change the transmission frequencies, so the technicians remained helpless in the face of what was going on. In both cases, the intrusion was immediately thought to come from within and the feds were called. Television studios were searched far and wide but without finding anything.
The hacker had probably managed to bypass the Studio Transmitter Link or had used an antenna (parabola).
In 2011 a Chicago programmer wrote a post on Reddit saying he knows the 2 authors of the Max Headroom interference, but does not reveal their real names simply by indicating them as J and K.
Although the same will then deny the whole thing in 2015.
30 years have passed and absolutely nothing is known about this story.