A three-part test for obscenity was established. The 1973 Miller decision by the Supreme Court modified the three-part test of the Roth decision. The second asked whether the work described sexual activity, against state law, in an offensive matter. The third asked whether the work lacked any literary, artistic, political or scientific value. This shifted the responsibility for defining obscenity from the national level to the community level.
Censorship can also occur at the local level.
Threats to community standards are often cited in issues of censorship. Identifying those standards may be difficult for the librarian, especially in a community with a diverse population that has a range of needs and interests. There are many Internet sites that identify the most commonly banned books due to community disapproval. On-Line has information on banned books and censorship attempts. Challenged and Banned Books is an ALA site listing the top ten most banned books and the top ten most challenged authors for the previous year.