The American Library Association states: A challenge is an attempt to remove or restrict materials, based upon the objections of a person or group. A banning is the removal of those materials. Challenges do not simply involve a person expressing a point of view; rather, they are an attempt to remove material from the curriculum or library, thereby restricting the access of others. As such, they are a threat to freedom of speech and choice.
The ALA Office of Intellectual Freedom (OIF) promotes awareness of challenges to library materials and celebrates freedom of speech during Banned Books Week. This event is observed during the last week of September of each year.
OIF compiles lists of challenged books as reported in the media and submitted to us by librarians and teachers across the country. For more about books challenged over the last 20 years, as well as information about classic novels that have been challenged and/or banned, please see Frequently Challenged Books.
Source: American Library Association. (2011). Banned & challenged books. Retrieved from http://www.ala.org/ala/issuesadvocacy/banned/index.cfm