Ask HN: Favorite technology predictions in science fiction?

I was recently re-reading The Diamond Age and was dumbstruck by the prescience of this quote: “One of the insights of the Victorian Revival was that it was not necessarily a good thing for everyone to read a completely different newspaper in the morning.”

Asimov in "The Caves of Steel"; Earth has a huge population that lives in huge cities, therefore it needs powerful computers as it has to track/police its massive population. Asimov guessed in 1953 that computers are a surveillance tool!

"R. Daneel came to his desk with a sheaf of papers. "And those are?" asked Baley. "A list of men and women who might belong to a Medievalist organization." "How many does the list include?" "Over a million," said R. Daneel. "These are just part of them." "Do you expect to check them all, Daneel?" "Obviously that would be impractical, Elijah." .... Baley said, abruptly, "How did you get your list?" "It was a machine that did it for me. Apparently, one sets it for a particular type of offense and it does the rest. I let it scan all disorderly conduct cases involving robots over the past twenty-five years. Another machine scanned all City newspapers over an equal period for the names of those involved in unfavorable statements concerning robots or men of the Outer Worlds. It is amazing what can be done in three hours. The machine even eliminated the names of non-survivors from the lists." "You are amazed? Surely you've got computers on the Outer Worlds?" "Of many sorts, certainly. Very advanced ones. Still, none are as massive and complex as the ones here. You must remember, of course, that even the largest Outer World scarcely has the population of one of your Cities and extreme complexity is not necessary."

I have no idea where the idea originated from but you see it sometimes in science fiction, that is the idea of mutable identity, from a superficial point of view. In other words the concept of anyone being able to represent themselves as they would like to through implants or body modification.

It seems the sci-fi trend for huge data storage back then was "crystals!". So were many of remote viewing devices, alien navigation systems and space fuel.

Vernor Vinge, everything but most immediately the notions if security hygene in "Rainbows End". Wearable augmented reality is ubiquitous, so anyone who corrupts your digital life can really impact not just your credit card but your perception of reality... So people develop security habits akin to personal hygiene in response.

You have to love a book where one of the superweapons is a top level security cert revocation...