Westerners, Americans especially, take their freedom of speech and press for granted. But freedom of speech and press, the kind we enjoy in modern western countries, is historically abnormal. Throughout 99% of the history of civilization, virtually every state has imposed restrictions, often harsh ones, on freedom of speech and press. And the rationale given for such restrictions was always the same: Security.
Such rationalizations seem absurd from the perspective of modern westerners, yet past ruling classes had a good reason to worry. Words have been the inspiration for pretty much every revolution and civil war in history. Words have toppled empires.
Just a couple of examples:
The writings of Martin Luther in the 1500's inspired a massive peasant revolt in Germany which resulted in the deaths of somewhere around 100,000 people. His writings also gave rise to the larger Protestant Reformation, which resulted in countless wars across Europe.
Inspired by a Bible given to him by a Christian missionary, Hong Xiuquan started a rebellion against the Qing Dynasty (known as the Taiping Rebellion). Estimates put the death toll at somewhere around 20 million.
I only used these two examples because they were at the forefront of my mind. There are literally hundreds if not thousands of other examples of words being used to inspire massive violence, which is why virtually all states throughout history have sought to restrict and control words.