In the United States, blackmail is generally defined as a crime of information, involving a threat to do something that would cause a person to suffer embarrassment or financial loss.
[1] By contrast, in the Commonwealth its definition is wider: for example the laws of England and Wales and Northern Ireland state that: A person is guilty of blackmail if, with a view to gain for himself or another or with intent to cause loss to another, he makes any unwarranted demand with menaces...[2][3]In popular culture, 'blackmail' involves a threat to reveal or publicize either substantially true or false information about a person or people unless certain demands are met.
[13] Blackmail was originally a term from the Scottish Borders meaning payments rendered in exchange for protection from thieves and marauders.
Alternatively, Mackay[obsolete source] derives it from two Scottish Gaelic words blathaich pronounced (the th silent) bla-ich (to protect) and mal (tribute, payment), cf.
One American legal scholar uses the example of a person who threatens to expose a criminal act unless he is paid money.