Taken from ALA website:
Banned Books Week (September 26 – October 2, 2021) is an annual event celebrating the freedom to read. Typically held during the last week of September, it spotlights current and historical attempts to censor books in libraries and schools. It brings together the entire book community — librarians, booksellers, publishers, journalists, teachers, and readers of all types — in shared support of the freedom to seek and to express ideas, even those some consider unorthodox or unpopular.
This year’s theme is “Books Unite Us. Censorship Divides Us.” Sharing stories important to us means sharing a part of ourselves. Books reach across boundaries and build connections between readers. Censorship, on the other hand, creates barriers.
The books featured during Banned Books Week have all been targeted for removal or restriction in libraries and schools. By focusing on efforts across the country to remove or restrict access to books, Banned Books Week draws national attention to the harms of censorship.
Check out the ALA website for more information on frequently challenged books and the top 10 most challenged books, etc.