If a book exists in the Universal Library that describes your life, every thought and action, in excruciating detail (and there is one true copy and a billion billion that are partly true, and as many that are factually false throughout), what about your privacy? 

I would point you to the short story by Jorge Luis Borges relating to the horror of the Librarians the imponderable trouble of a library that contains every possible placement of character - indefinite bookcases with no proper catalog that could point you to that one true book of your life. I would point you to the proposals I've written already, in that searching such a library electronically has so many issues of technology, let alone context that finding that one true book would still be (practically) insurmountable by anyone, including you.

However, the answer lies in context. Imagine a random person discovering a series of books about your life. Which of them is true, which are partly true or utterly false? How would that person know? How would that person know what you thought of April 4th, 1990 at noon as you walked down the sidewalk and saw a bird between you and the rest of the sidewalk? No one except you (if you remembered it or could recall it). Even you might be hard pressed to recall such a day or such a bird. 

Context is the ultimate answer to finding anything in a library with books enough to blanket the universe, and context is also the answer to privacy. Even you might not be able to break through to your own private book, or recognize it as your one true book even when you did.

It is the Contextual-Engine that becomes your source of greatest privacy, and your most perfidious frustration. In some cases, the amount of refinement of your search would require you to write your own book in order to find it. How deep you want that rabbit-hole to go will depend on how far you dig the hole; you're the only one who might then even fit, if you've made room for yourself. Nosce te ipsum.

Quite Literally Yours,

The Librarian