From the American Library Association:
Censorship can be subtle, almost imperceptible, as well as blatant and overt, but, nonetheless, harmful. As John Stuart Mill wrote in On Liberty:
If all mankind minus one, were of one opinion, and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person, than he, if he had the power, would be justified in silencing mankind. Were an opinion a personal possession of no value except to the owner; if to be obstructed in the enjoyment of it were simply a private injury, it would make some difference whether the injury was inflicted only on a few persons or on many. But the peculiar evil of silencing the expression of an opinion is, that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who hold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth: if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collision with error.
— On Liberty, John Stuart Mill
Banned Books Week began back in 1982. It is always designated as the last week in September. It is the only national celebration of the freedom to read what we want. More than a thousand challenges from every state have come in since 1982.
The following list is the top 100 banned or challenged classics: