Books are the ultimate speech because they exist long after the speaker. Therefore the burning of books is a terrible violation of free speech.
"It's fine work. Monday bum Millay, Wednesday Whitman, Friday Faulkner, burn 'em to ashes, then bum the ashes. That's our official slogan." (ch 1)
This quote is particularly sad because most of the people in this society have never even read these writers.