Read the riot act

This one isn't a metaphor at all. It's a literal law. The Riot Act of 1714 gave British authorities the power to declare any gathering of twelve or more people unlawful. An official had to read a specific, formally worded proclamation aloud; if the crowd didn't disperse within an hour of hearing it, officers could use force to break it up. Everyday use of the phrase to mean "a stern telling-off" took hold in the 1800s.