"Read them the Riot Act." You've been threatened with it before. But what is it? Did the threatener do it right? We at SCOPE-TECH, knowing the Executive Secretary of the American Dialectic Society, have undertaken the effort to discover the origins of this phrase. We only provide information. How you use or abuse this information is your responsibility.
History: The Riot Act was a law passed by the British Parliament in 1714 and took effect in 1715 (which is why it is commonly know as "The Riot Act of 1715"). This was a period of civil unrest in Britain as the new Hanoverian king, George I, tried to quell Catholic Jacobite riots, and the threatened invasion by supporters of the deposed Stuarts. The law required that if 12 or more people were gathered for an unlawful purpose, the local magistrate was required to read the following to the crowd:
Our Sovereign Lord the King chargeth and commandeth all persons being assembled immediately to disperse themselves, and peaceably to depart to their habitations or to their lawful business, upon the pains contained in the act made in the first year of King George for preventing tumultuous and riotous assemblies. God save the King.
If after one hour, the crowd had not dispersed, they were subject to arrest and harsh penalties. Here is the full text of the Riot Act. Imagine reading this to an angry mob, and then giving them an entire hour to disperse.
Today: Oddly, the Riot Act remained in effect longer than one might think. It was either repealed in 1973, or superseded by the Public Order Act of 1986. And, the Riot Act is actually STILL in effect in Canada. However, being British law, it's been pretty toothless in the United States for over 225 years.
Summary: Though the threat of the Riot Act only holds the force of law for my Canadian cousins, it is often applied to groups of less than a dozen, and the hour time frame is regularly ignored, the implication of having it read to you is that you've ticked off the authorities, and you'd better knock it off, straighten up, and fly right.
So, while not legally required to obey the Riot Act, it may be in one's best interests to comply. And if you decide to read someone the Riot Act, you may as well make them comply with the Stamp Act of 1765.