read the riot act
Britain’s Riot Act of 1715 stated that when 12 or more people were engaged in a riot, any magistrates on hand could command them to disperse. Anyone not obeying the command could be arrested for a felony. So reading the riot act is a public warning of dire consequences if certain behavior is to continue.
General use of riot act in this sense appears as early as 1731. From The Gentleman’s Magazine of that year:
Speaking of the riot-act he says.
The familiar wording of read the riot act appears in 1819. From a 17 December letter by a William Bradford:
She has just run out to read the riot act in the Nursery.
The Riot Act was repealed in 1973.
(Source: Oxford English Dictionary, 2nd Edition)
Copyright 1997-2014, by David Wilton