Those in charge of American libraries and commercial bookstores make acquisition decisions every day. Unless you believe that every rejection is somehow a "banning" of that title, you must accept the process as a normal part of institutional management. Now, "weeding" and selectively tossing out the printed legacy of mankind (which is also a normal part of contemporary library management) might be considered "banning," but those doing the tossing will never admit it.
How about a week for "banished books" instead? An appreciation for all those titles that were once preserved but are now being systematically trashed by their former caretakers.