A threat is an act of coercion wherein an act is proposed to elicit a negative response. It is a communicated intent to inflict harm or loss on another person. It is a crime in many jurisdictions. Libertarians hold that a palpable, immediate, and direct threat of aggression, embodied in the initiation of an overt act, is equivalent to aggression itself, and that proportionate defensive force would be justified in response to such a threat, if a clear and present danger exists.
In Brazil, the crime of threatening someone, defined as a threat to cause unjust and grave harm, is punishable by a fine or three months to one year in prison, as described in the Brazilian Penal Code, article 147. Brazilian jurisprudence does not treat as a crime a threat that was proferred in a heated discussion.
The German Strafgesetzbuch § 241 punishes the crime of threat with a prison term for up to one year or a fine.
In the United States, federal law criminalizes certain true threats transmitted via the U.S. mail or in interstate commerce. It also criminalizes threatening the government officials of the United States. Some U.S. states criminalize cyberbullying.