Read the Riot Act

Etymology:

• British Parliament passed the Riot Act in 1714 that illustrated that if twelve or more people get gathered in a riotous and illegal manner, then a magistrate can break them up by just reading the first few words of the riot act. They’ve to leave within an hour and if they didn’t do so then they’d be liable to severe punishment as they’d be involved in breaking the law of the country. Reading the riot act is now considered to be an expression to warn someone in the strongest manner.