Huh? It was fairly common for typewriter ribbons to be destroyed where confidential information was typed, as it was possible to acquire previously typed characters.
Obviously. But how obviously to someone who assumes anything without an Internet connection is constitutionally unsurveillable thereby? How does it occur to you to destroy a ribbon, or consider all the other methods by which a sufficiently motivated adversary will defeat your toy air gap, if you believe your air gap isn't a toy?
Of course we are deep into the realm of movie plots already, where we've fantasized a superstate-or superhuman-level adversary still somehow capable of being defeated by "going crude." But if that's where we're going to hang out, why half-ass it?
... you would be shocked by how much could be surveilled back then. Pretty much any voice communicated were sent in the clear. It didn't much matter whether it was sent over wire or over the air. Snail mail was virtually always sent as clear text. Even digital communications were rarely encrypted. Even ignoring the legality of it, few people had the creativity to envision a world of secure communications or wanted to expend their (limited) computing power on it. There were, of course, exceptions like the military.
Who's being sarcastic? My point is precisely that a typewriter is not a magic bullet, and I lived back then; I assure you I am very well aware.
I really do grow frightened of people's reading comprehension on the internet, having observed a qualitative decline especially in the last twelve months. Granted, this seems more due to indolence than actual impairment, thus far at least, but atrophy must eventually tell.
Of course we are deep into the realm of movie plots already, where we've fantasized a superstate-or superhuman-level adversary still somehow capable of being defeated by "going crude." But if that's where we're going to hang out, why half-ass it?