<P> The liberty of the press is indeed essential to the nature of a free state; but this consists in laying no previous restraints upon publications, and not in freedom from censure for criminal matter when published . Every freeman has an undoubted right to lay what sentiments he pleases before the public; to forbid this, is to destroy the freedom of the press; but if he publishes what is improper, mischievous or illegal, he must take the consequence of his own temerity. (4 Bl . Com. 151, 152 .) </P> <P> This view was the common legal understanding at the time the US constitution was adopted . Only later have the concepts of freedom of speech and the press been extended (in the United States, the United Kingdom, and other countries sharing their legal tradition) to protect honest error, or truth even if published for questionable reasons . </P> <P> Prior restraint is often considered a particularly oppressive form of censorship in Anglo - American jurisprudence because it prevents the restricted material from being heard or distributed at all . Other forms of restrictions on expression (such as actions for libel or criminal libel, slander, defamation, and contempt of court) implement criminal or civil sanctions only after the offending material has been published . While such sanctions might lead to a chilling effect, legal commentators argue that at least such actions do not directly impoverish the marketplace of ideas . Prior restraint, on the other hand, takes an idea or material completely out of the marketplace . Thus it is often considered to be the most extreme form of censorship . The United States Supreme Court expressed this view in Nebraska Press Assn . v. Stuart by noting: </P> <P> The thread running through all these cases is that prior restraints on speech and publication are the most serious and the least tolerable infringement on First Amendment rights . A criminal penalty or a judgment in a defamation case is subject to the whole panoply of protections afforded by deferring the impact of the judgment until all avenues of appellate review have been exhausted . Only after judgment has become final, correct or otherwise, does the law's sanction become fully operative . </P>

Why are courts so hesitant to allow prior restraint in restricting speech