„There is a fine line between free speech and hate speech. Free speech encourages debate whereas hate speech incites violence.“

Tweet https://twitter.com/geertwilderspvv/status/787257675952324608 (15 October 2016)
2010s

Counterterrorism and Cybersecurity: Total Information Awareness (2nd Edition), 2015

Cyber Rights — cited in [DeCandido, GraceAnne A., Cyber Rights: Defending Free Speech in the Digital Age, Booklist, American Library Association, 94, 22, 1932, August 1998]
Cyber Rights

Address at Columbia University (1991)
Context: "Our lives teach us who we are." I have learned the hard way that when you permit anyone else's description of reality to supplant your own — and such descriptions have been raining down on me, from security advisers, governments, journalists, Archbishops, friends, enemies, mullahs — then you might as well be dead. Obviously, a rigid, blinkered, absolutist world view is the easiest to keep hold of, whereas the fluid, uncertain, metamorphic picture I've always carried about is rather more vulnerable. Yet I must cling with all my might to … my own soul; must hold on to its mischievous, iconoclastic, out-of-step clown-instincts, no matter how great the storm. And if that plunges me into contradiction and paradox, so be it; I've lived in that messy ocean all my life. I've fished in it for my art. This turbulent sea was the sea outside my bedroom window in Bombay. It is the sea by which I was born, and which I carry within me wherever I go.
"Free speech is a non-starter," says one of my Islamic extremist opponents. No, sir, it is not. Free speech is the whole thing, the whole ball game. Free speech is life itself.

"Quotes", The Educated Imagination (1963), Talk 6: The Vocation of Eloquence

2010s, Who's too Weak to Live with Freedom? (2013)

Remarks by the President to the UN General Assembly https://www.whitehouse.gov/the-press-office/2012/09/25/remarks-president-un-general-assembly (25 September 2012), quoted in "President Obama Condemns Both ‘Disgusting’ Anti-Islam Video And ‘Mindless’ Violence Before The U.N." http://www.mediaite.com/tv/president-obama-condemns-both-disgusting-anti-islam-video-and-mindless-violence-before-the-u-n/ by Andrew Kirell, mediaite.com.
2012
Context: In every culture, those who love freedom for themselves must ask themselves how much they're willing to tolerate freedom for others. That is what we saw play out in the last two weeks, as a crude and disgusting video sparked outrage throughout the Muslim world. Now, I have made it clear that the United States government had nothing to do with this video, and I believe its message must be rejected by all who respect our common humanity. It is an insult not only to Muslims, but to America as well. [... ] I know there are some who ask why we don't just ban such a video. And the answer is enshrined in our laws: Our Constitution protects the right to practice free speech. Here in the United States, countless publications provoke offense. Like me, the majority of Americans are Christian, and yet we do not ban blasphemy against our most sacred beliefs. As President of our country and Commander-in-Chief of our military, I accept that people are going to call me awful things every day -- (laughter) -- and I will always defend their right to do so. (Applause.) [... ] The strongest weapon against hateful speech is not repression; it is more speech -- the voices of tolerance that rally against bigotry and blasphemy, and lift up the values of understanding and mutual respect. [... ] On this we must agree: There is no speech that justifies mindless violence. (Applause.) There are no words that excuse the killing of innocents. There's no video that justifies an attack on an embassy. There's no slander that provides an excuse for people to burn a restaurant in Lebanon, or destroy a school in Tunis, or cause death and destruction in Pakistan.

Anarchism & American Traditions (1908)
Context: What has Anarchism to say to all this, this bankruptcy of republicanism, this modern empire that has grown up on the ruins of our early freedom? We say this, that the sin our fathers sinned was that they did not trust liberty wholly. They thought it possible to compromise between liberty and government, believing the latter to be "a necessary evil," and the moment the compromise was made, the whole misbegotten monster of our present tyranny began to grow. Instruments which are set up to safeguard rights become the very whip with which the free are struck.
Anarchism says, Make no laws whatever concerning speech, and speech will be free; so soon as you make a declaration on paper that speech shall be free, you will have a hundred lawyers proving that "freedom does not mean abuse, nor liberty license"; and they will define and define freedom out of existence. Let the guarantee of free speech be in every man's determination to use it, and we shall have no need of paper declarations. On the other hand, so long as the people do not care to exercise their freedom, those who wish to tyrannize will do so; for tyrants are active and ardent, and will devote themselves in the name of any number of gods, religious and otherwise, to put shackles upon sleeping men.

see “Nazi”
" Latest college shenanigans by the Regressive Left: censorship at Pomona and UCLA; Wellesley student paper publishes “we need free speech but...” editorial https://whyevolutionistrue.wordpress.com/2017/04/21/latest-news-about-college-shenanigans-by-the-regressive-left-censorship-at-pomona-and-ucla-wellesley-student-paper-writes-we-need-free-speech-but-article/" April 21, 2017

Speech at Hall of Science c.1880 quoted in An Autobiography of Annie Besant; reported in Edmund Fuller, Thesaurus of Quotations (1941), p. 398; reported as unverified in Respectfully Quoted: A Dictionary of Quotations (1989).
Attributed

Free Software

The Liberals' Mistake (1987)
Context: Liberals placed an unreasonable amount of faith in large institutions: unions, foundations, big government, large corporations, and universities. These institutions are based on principles that are antithetical to democracy. They are not democratic, they are hierarchical: Someone is at the top and everybody else is at the bottom. Their policies are not made democratically, they are made at the top. These institutions are also not egalitarian. They operate by administrative discretion and authority, not the rule of law: There is no legislature, no group lawmaking body.
The individual in the large organization does not have the kind of constitutional rights that an individual in the society at large has. There are no protections of autonomy and free speech. Employees can be fired for many reasons. We need to constitutionalize large organizations to protect the people within them, to ensure that they can be politically outspoken.

"Freedom of Speech as I See It Today", Journalism Quarterly, vol. 18 (June 1941), p. 158.

Source: Mark Twain's Notebook (1935), p. 393

The Beast of Property (1884)

Quotes 1990s, 1995-1999, The Common Good (1998)
Context: Property rights are not like other rights, contrary to what Madison and a lot of modern political theory says. If I have the right to free speech, it doesn't interfere with your right to free speech. But if I have property, that interferes with your right to have that property, you don't have it, I have it. So the right to property is very different from the right to freedom of speech. This is often put very misleadingly about rights of property; property has no right. But if we just make sense out of this, maybe there is a right to property, one could debate that, but it's very different from other rights.

Variant translation: In a free state, both the tongue and the mind ought to be free.
From Suetonius, The Twelves Caesars, ch. 28

"The Privilege of the Grave" (1905)
Context: As an active privilege, [free speech] ranks with the privilege of committing murder: we may exercise it if we are willing to take the consequences. Murder is forbidden both in form and in fact; free speech is granted in form but forbidden in fact. By the common estimate both are crimes, and are held in deep odium by all civilized peoples. Murder is sometimes punished, free speech always.