Although "speech" is often distinguished from "action," from a broader viewpoint the expression of ideas through speech or other media is itself a form of human action, involving the allocation of means to ends in the same manner as other actions, and hence requiring scarce resources like all other human action. In popular discussion, the notions of freedom of speech and of expression are often fuzzy and indefinite, giving rise to many controversies. As we shall show in more detail in Section 5, these concepts become precise when they are framed properly in terms of property rights. Censorship is the initiation of force against persons or their property with the intent or effect of repressing, modifying, or imposing particular forms of speech or expression. Speech or expression may be censored prior to publication, or it may be censored after the fact by means of force administered against speakers, authors, or publishers. In either case, censorship is, by definition, a type of aggression against property and should thus be viewed as another form of market intervention.