The Library of Congress regularly receives requests for books that don't exist

The Library of Congress is rumored to contain certain secret books that are publicly displayed as not existing, but those rumors are just… rumors. The Library receives many requests each year by random citizens to see the President’s Book of Secrets, along with many other hidden, conspiratorial books. You may have heard of the Book of Secrets in the second National Treasure movie, but it was a made-up book for the film. The book does not exist as far as anyone knows, and if it did exist, why would it be loaned out to random citizens?