One of better summaries of why privacy is critical to free societies.
Now, there's a reason why privacy is so craved universally and instinctively. It isn't just a reflexive movement like breathing air or drinking water. The reason is that when we're in a state where we can be monitored, where we can be watched, our behavior changes dramatically. The range of behavioral options that we consider when we think we're being watched severely reduce. This is just a fact of human nature that has been recognized in social science and in literature and in religion and in virtually every field of discipline. There are dozens of psychological studies that prove that when somebody knows that they might be watched, the behavior they engage in is vastly more conformist and compliant. Human shame is a very powerful motivator, as is the desire to avoid it, and that's the reason why people, when they're in a state of being watched, make decisions not that are the byproduct of their own agency but that are about the expectations that others have of them or the mandates of societal orthodoxy. ...a society in which people can be monitored at all times is a society that breeds conformity and obedience and submission, which is why every tyrant, the most overt to the most subtle, craves that system. The other really destructive and, I think, even more insidious lesson that comes from accepting this mindset is there's an implicit bargain that people who accept this mindset have accepted, and that bargain is this: If you're willing to render yourself sufficiently harmless, sufficiently unthreatening to those who wield political power, then and only then can you be free of the dangers of surveillance.