In Cyberbullying, Trolling, and Cyberstalking: the Dark Side of Free Speech (part 1a), computer security expert witness Steve Burgess answers the question What is Free Speech?
To listen to, read, or watch the news, it is clear that there is broad misunderstanding about the right to free speech. It is not the freedom to say anything to anyone anywhere, but rather a prohibition to keep the government from denying us the right to express ourselves. The Bill of Rights asserts that we have certain freedoms simply by dint of being born human beings.
We treasure our freedoms and freedom of expression or speech is one of the most sacred. Having this right allows us to speak truth to power and to satirize fools. In fact, one of the earliest forms of protected speech may have been the Celtic bards who worked for tribal kings, satirizing poor (or opposing) rulers, but immune from retribution under Brehon law many hundreds of years ago, or even thousands of years under European Celtic tradition.