Jewish and Israeli history are the prime examples.
The enemies are always changing the immutable, of course, but even “our side” is often embarrassed at Jewish heroism and self-defence, or “Gadol stories” which don’t fit the new narrative.
They can “fix” information saved online; they can’t do the same if you have a print copy in your home.
Tip: It may be tattered, old, cover missing, and so on. Don’t throw it out!