"I believe in free speech, but..." is the censor's equivalent of "I'm not racist, but..." The "but" reveals the truth.
ETA: A dictator is literally "the one who speaks". Only would-be dictators dream of silencing others.
ETA 2: "If all printers were determined not to print anything till they were sure it would offend nobody, there would be very little printed."
ETA 3: Mark Twain is often wrongly credited with a quote I like: "Censorship is telling a man he can't have a steak just because a baby can't chew it." Whoever actually said it might've been inspired by this:
"How anybody expects a man to stay in business with every two-bit wowser in the country claiming a veto over what we can say and can't say and what we can show and what we can't show — it's enough to make you throw up. The whole principle is wrong; it's like demanding that grown men live on skim milk because the baby can't eat steak." —Robert A. Heinlein, The Man Who Sold the Moon
ETA 4: "Our liberty depends on the freedom of the press, and that cannot be limited without being lost." —Thomas Jefferson
ETA 5: On "speaking to truth to power":
"All censorships exist to prevent anyone from challenging current conceptions and existing institutions. All progress is initiated by challenging current conceptions, and executed by supplanting existing institutions. Consequently the first condition of progress is the removal of censorship." —George Bernard Shaw
ETA 6: I've shared this before, but it's always good:
"To suppress free speech is a double wrong. It violates the rights of the hearer as well as those of the speaker." —Frederick Douglass, "A Plea for Free Speech in Boston"
ETA 7: In the comments at I BELIEVE IN FREE SPEECH, BUT… | Pandaemonium, I said:
I am always struck by how “but” works. People who say “I’m not a racist, but…” go on to expose their racism. People who say, “I believe in free speech, but…” go on to expose their opposition to free speech. Free speech is not the right to say what you want to say—the worst tyrants support their right to say what they want to say. Free speech is the right for others to say what you do not want to hear.Jody Wheeler responded:
There’s a saying I taught others when I was a therapist, taught to me by another therapist, who in turn had it taught to him: “Everything before the ‘but’ is bullshit.”
Amazing how many buts you encounter in the world.ETA 8: An older post of mine: The curious contradictions of censorial socialists, and a few comments about Charlie Hebdo