Censorship—or prior restraint—is the halting of a message by the government before the message is uttered. In the United States it has been called the "most serious, least tolerable" infringement of free speech because it halts speech before it can reach the marketplace of ideas (Nebraska Press Association v. Stuart, 1976). That is, the speech is not subject to discussion, debate, or rebuttal because it is stifled before such opportunities can be pursued. The word censorship has been applied to a wide variety of activities— including newspapers deciding not to publish controversial cartoons, department stores refusing to sell certain magazines, or private organizations firing newsletter editors because of the articles they published. None of these examples constitute censorship, however, because they do not involve government action.
Some governments defend control over expression on the grounds that full debate, particularly of governmental actions, is risky, in that it can undermine the government or be detrimental to national security. Even governments that adhere to doctrines prohibiting prior restraint, however, recognize that not all speech is allowed in all circumstances. Certain kinds of speech, such as that which might harm national security, cause a violent breach of the peace, or tempt a person into illegal conduct, can be restrained by the government. In the United States, recognition of the right to impose censorship in exceptional situations was established in the 1931 case of Near v. Minnesota, and has been reaffirmed in subsequent cases. For example, justices on the U.S. Supreme Court have noted that words that are likely to cause "direct, immediate and irreparable" harm to the country may be censored (New York Times Co. v. United States, 1971).
Governments that guarantee expressive rights without prior restraint do so generally on the basis that robust, open debate—even when expression is obnoxious or con-troversial—is the better avenue for decision-making.
Some confusion over the reach of the prior restraint doctrine has emerged because of governmental control over broadcasting, particularly in the United States and Canada. Broadcasting is regulated by the Federal Communications Commission in the United States, and by the Canadian Radio-Television and Telecommunications Commission in Canada. Neither agency has direct control over the content of broadcasting, but each provides a mechanism through which broadcasters make their messages available to listeners and viewers through a system of licensing. Such governmental regulation in both the United States and Canada has come to be known as the trusteeship model. The model is based on the rationale that the airwaves constitute a natural resource and, as such, belong to the citizenry. Because broadcasting’s electronic spectrum is limited, there must be, therefore, some mechanism for picking and choosing among potential broadcasters. Broadcasters, then, are acting as trustees for the public in their use of the airwaves. Both Canada’s Broadcasting Act of 1991 and the United States’ Telecommunications Act of 1996, which amended the Communications Act of 1934, stipulate that individual broadcasters maintain control over the content of their broadcasts, but also prohibit certain kinds of communication, such as indecent or obscene speech.
