@BarryZuckerkorn that is true. After all, the internet was designed as a tool for communication, so you do need to have your information public to a certain degree. But you also want to have confidentiality, so that your message only gets to your desired audience. That's the bigger problem that all these platforms have.
Imagine the level of information about us all the historians of the future will have available tho. 😁
I, for one, don't know how even a certain level of privacy can be achieved in the Fediverse. ActivityPub tries to solve the issue by controlling the access from the get-go, as far as I can see: you compose a post, then set it's visibility to whatever you like before sending the post. Then that privacy setting gets preserved in the original post. That's it. You cannot modify it. But if the post is not sent to a certain server, then it doesn't need to be deleted.
Diaspora, from what I've heard, takes a different approach: the top-level poster owns the thread, so if there is some issue with trolls hijacking your posts or whatnot, you can simply delete their comments. Yet I don't know what happens when you delete your top-level post. Will the deletion federate? Are other pods only having access to your post or copying it over?
On Friendica you can activate a setting to disallow anonymous access to your account. That means you can still see what goes to other servers (i.e. try accessing my profile from Beehaw), but when you try to access my profile from the server I am on, you get a Restricted access screen. As I am not a public person, I decided this is a better way to keep my profile a bit more private. One could theoretically still compile all the posts I've sent to all the other servers since I joined, but that's it.
Meta could have probably done a similar thing here.