Without doubt, the data mining of keeping track of what you read goes back to the first Library Card issued from the Great Library at Alexandria.   It has of course become ever more intrusive and prevalent since the advent of the internet, after all targeted advertising finds its targets by looking at the past history of pages you have accessed.  The only thing new here is the level of detail when combined with AI is enough that it's possible for a computer to actually figure out what you are THINKING, not just what you are reading or looking at.  It can keep tabs on how long you spent on a given page.  Which parts of a book did you go back to reread?  The more stuff you read, the more data you give the AI to work with, until it can build a model of the way your mind works.  What kind of romance or porn novels do you read?  Have you read any books about making explosives?  Did you read the Communist Manifesto?

Of course, at this point it's become almost impossible to find anything to read that is truly subversive.  Also tough to find anything remotely resembling the truth that deviates from what Da Goobermint approves as truth.  It's hard to imagine how any kind of revolutionary movement could even get started anymore.  The minute it gets any traction AI bots will pick it up and a Cointelpro designed to break it up.

Stick to reading paperbacks from used bookstores, and pay cash.

RE

https://www.fastcompany.com/90996547/e-books-are-fast-becoming-tools-of-corporate-surveillance

E-books are fast becoming tools of corporate surveillance

RE