Right, I think it's just a case of following the technologies throughout the ages in alignment with the political/cultural climate. Computers are "newcomers",

Right, I think it's just a case of following the technologies throughout the ages in alignment with the political/cultural climate. Computers are "newcomers", and by that point there was big political push for mass surveillance and anti-privacy propaganda was picking up. People have gotten less privacy conscious as time goes on so our laws regarding technology reflect that. Also the nature of the tech matters, I think. Post is fairly simple to ensure privacy with, same with phone. You have to go out of your way to open things up or record them. Phones calls, by their nature, exist on the wire while they're happening. But computers store things and that's a huge part of their usefulness. If you're already saving stuff to disk, which you probably are, there's no friction really with using that for nefarious uses. For example, request logging in a corporate environment. Although this doesn't explain things like recording screens.