If you had enough motivation, you could learn to decode the picture by squinting, and understand the audio by enough exposure. That came very handy to many a teenager on late Saturday evenings.
My father was in electronics and schematics of pirate decoders were being passed around between friends/colleagues (this was before the web!) He got the schematics and built one.<p>Later in the 90's, when TV cards became cheap enough I got one for my computer then there were software to decode the signal.
Interesting! Over in the UK we had <a href="https://en.wikipedia.org/wiki/VideoCrypt" rel="nofollow">https://en.wikipedia.org/wiki/VideoCrypt</a><p><a href="https://downloads.bbc.co.uk/rd/pubs/reports/1995-11.pdf" rel="nofollow">https://downloads.bbc.co.uk/rd/pubs/reports/1995-11.pdf</a>
An ancient Easter egg is revealed at the end of this interesting article. The "all free" code was `1337` or "leet" in leet!
<i>Asking for "TBA 970" delay chips in electronic stores prompted employees to offer the full list required to build a "decodeur pirate"</i><p>Good ol' civil disobedience. Love it.
[2020]