The big thing that changed was in regard to long range messages.
The biggest problem in the past was secure coordination. For example, the battle plans at the Battle of Antietam were discovered in cigars.
Thus, the calculus was that people could keep their stuff private, but if they were trying to coordinate with others, communications were able to be cracked.
However, now, people can do secure, encrypted communication easily with dozens of people worldwide. This changes the calculus of what they can accomplish. A person with a locked briefcase at home is pretty limited in what kind of stuff they can coordinate. A person securely communicating with dozens of people worldwide, can accomplish quite a lot without discovery.
The biggest problem in the past was secure coordination. For example, the battle plans at the Battle of Antietam were discovered in cigars.
Thus, the calculus was that people could keep their stuff private, but if they were trying to coordinate with others, communications were able to be cracked.
However, now, people can do secure, encrypted communication easily with dozens of people worldwide. This changes the calculus of what they can accomplish. A person with a locked briefcase at home is pretty limited in what kind of stuff they can coordinate. A person securely communicating with dozens of people worldwide, can accomplish quite a lot without discovery.
This changes the calculus from the 1800s.