'Monarchs had, so to speak, materialized oppression; the democratic republics of the present day have rendered it as entirely an affair of the mind as the will which it is intended to coerce. Under the absolute sway of one man the body was attacked in order to subdue the soul; but the soul escaped the blows which were directed against it and rose proudly superior. Such is not the course adopted by tyranny in democratic republics; there, the body is left free, and the soul is enslaved. The master no longer says, "You must think as I do, or you shall die"; but he says: "You are free to think differently from me and to retain your life, your property, and all that you possess; but you are henceforth a stranger among your people. You may retain your civil rights, but they will be useless to you, for you will never be chosen by your fellow citizens if you solicit their votes; and they will affect to scorn you if you ask for their esteem. You will remain among men, but you will be deprived of the rights of mankind. Your fellow creatures will shun you like an impure being; and even those who believe in your innocence will abandon you, lest they should be shunned in their turn. Go in peace! I have given you your life, but it is an existence worse than death."

Alexis de Tocqueville, 'Democracy in America,' volume 1, chapter 15.

Later in that same chapter, he says straigt out: '...freedom of opinion does not exist in the United States.' And also this:

'Works have been published in the proudest nations of the Old World expressly intended to censure the vices and follies of the times....But the ruling power in the United States is not to be made game of....No writer, whatever be his eminence, can escape paying this tribute of adulation to his fellow citizens. The majority lives in the perpetual utterance of self-applause, and there are certain truths which the Americans can learn only from strangers or from experience.'

I think that last sentence is especially pertinent to the experience of the 9/11 truth movement.