Censorship refers to the suppression of speech or writing that is considered to be a bad influence on society. Moral censorship is usually imposed by governments, though religious and other authorities might also target speech or writing that they do not approve of. Some content, such as books as movies, might be censored because they are judged to cross the boundaries of what is considered decent in a society at a point in time. For instance, the nation of Iran censored a recent issue of the National Geographic magazine which carried a cover photo on the theme "love". The Roman Catholic Church maintained an "index" of books that were forbidded to read. The Soviet Union censored work of many authors including Nobel laureates Boris Pasternak and Aleksandr Solzhenitsyn. In the United States, novels such as James Joyce's Ulysses, D. H. Lawrence's Lady Chatterley's Lover, and Henry Miller's Tropic of Cancer were banned for many years until the courts ruled in their favor.
Another target of censorship is so-called state secrets, information whose spread is regarded as damaging to the military, political or economic interests of a nation. For example, the government of a country might object to the publication of accurate photographs of its defence establishments or airports that hostile nations might exploit. While such concerns might be viewed as justified by the government of a country, we have to be careful not to suppress political opinions that are critical of the current political leadership under the guise of patriotism and national interest.
Other targets of censorship include scientific research, where research results contrary to currently-held beliefs might be suppressed by those who control the outlets for publication. Even the lyrics of popular music (especially rap music) often run into opposition from people who seek to censor them.
Censorship is not a simple issue. Some even see restrictions on hate speech (writing or speech expressing malice towards ethnic, religious, or social groups) as censorship, though others feel that silencing such speech enhances harmony in society. Yet others worry about self-censorship, the way we restrain ourselves, due to political or economic pressures, from saying what we really want. Whatever our personal views on censorship, it is clear that not saying something often has as much impact on what we say.