American Library Association Definition of Censorship

Censorship -- The change in the access status of material, made by a
governing authority or its representatives. Such changes include:
exclusion, restriction, removal, or age/grade level changes.

Adopted by the Intellectual Freedom Committee at the 1986 American
Library Association Annual Conference

[This definition is flawed in that it only recognized governmental
censorship.  - mech@eff.org]