Final answer:
Prior restraint is the act by which the government prevents material from being published, and it is done to protect national security and avoid harm to individuals or society. One notable case related to prior restraint is the Pentagon Papers case in 1971, where the Supreme Court ruled in favor of protecting freedom of the press and limited the government's ability to impose prior restraint.
Step-by-step explanation:
The act by which government prevents material from being published is called prior restraint. Prior restraint refers to a government action that stops someone from publishing or expressing something before they are able to do it. The concept of prior restraint comes into play when the government believes that the publication of certain information may pose a threat to national security or cause harm to individuals or the society.
One significant case related to prior restraint is the Pentagon Papers case in 1971. The U.S. government tried to stop the New York Times and the Washington Post from publishing classified information about the Vietnam War. However, the Supreme Court ruled that prior restraint should only be allowed in very limited circumstances, such as when revealing troop movements or the names of undercover operatives. It emphasized the importance of freedom of the press and the right to publish information.
In conclusion, the act by which government prevents material from being published is known as prior restraint, which involves restrictions on publishing or expressing certain information before it is released.