Blackmail
Overview
In common usage, blackmail is a crime
Crime
Crime is the breach of rules or laws for which some governing authority can ultimately prescribe a conviction...

 involving threats to reveal substantially true
Substantial truth
Substantial truth is a legal doctrine affecting libel and slander laws in common law jurisdictions such as the US or the UK.Under the United States law, a statement cannot be held to be slanderous or libelous if it is true; the substantial truth doctrine extends this protection by holding that a...

 or false information about a person to the public, a family member, or associates unless a demand is met. It may be defined as coercion
Coercion
Coercion is the practice of forcing another party to behave in an involuntary manner by use of threats or intimidation or some other form of pressure or force. In law, coercion is codified as the duress crime. Such actions are used as leverage, to force the victim to act in the desired way...

 involving threats of physical harm, threat of criminal prosecution, or threats for the purposes of taking the person's money or property. It is the name of a statutory offence in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, England and Wales
England and Wales
England and Wales is a jurisdiction within the United Kingdom. It consists of England and Wales, two of the four countries of the United Kingdom...

, Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

, and Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

, and has been used as a convenient way of referring to other offences, but was not a term of art in English law
English law
English law is the legal system of England and Wales, and is the basis of common law legal systems used in most Commonwealth countries and the United States except Louisiana...

 before 1968.
 
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