A common definition of Freedom of Speech is that people are free to say or discuss whatever they wish in public without fear of retribution. This is not what it is. A better, real world, definition of Freedom of Speech is that people can say anything as long as it’s more or less in agreement with what I think.
Every society has its restrictions on what people can and can’t say. These may be defined as blasphemy laws, political correctness or whatever, depending on the society, but the restrictions always exist. There is particular confusion about this in the UK today, since we are going through a transition with regard to what people are allowed to say. The rules are currently unclear, and in flux, so there can easily be an impression that any view can be expressed. This is not the case.
The penalties for ignoring restrictions on speech can be serious. In the past, both Catholics and Protestants have burned those who disagree with them at the stake. Killing of dissidents by ISIS seems to be normal. In Germany recently two elderly women have been imprisoned for disagreeing with the Holocaust ( Ursula Haverbeck, 89 and Monika Schaefer.) In the UK, Hate Crime legislation teeters constantly on being used to control debate; there is a fundamental problem with such laws, since crimes of violence or harassment can be prosecuted under already existing laws. Adding an issue of what someone thinks, or their intention in what they say, is a serious step to take. However, regardless of any of this, freedom of expression is effectively controlled by whoever controls the Mass Media. See Media and Truth Part Company over Syria for an example of this.
The tragedy here is that every society is hamstrung in its search for truth by the impossibility of open debate. Truth is the casualty, and when truth suffers we all do. Truth is always the first casualty in war, since the two sides must have sufficiently different beliefs that they think them worth killing and dying for. It is possible, of course, that all the lies are on the opposing side to yours, but without the ability to debate openly, including the view from the other side, how would you ever know?
This is something that, regrettably, will never change. There will always be an accepted, established view in every society, enforced and promoted by those with the power or money to do so. The only remedy, and it is only partial, is the micro-scale one of individuals being aware of the problem and making a deliberate effort to think outside of their society’s box.