On the point of arresting people planning to protest, many protest around the world were fueled by the use of social media/messaging apps. So in that case its not obvious that it has a negative effect on democracy.
These happened due to networks, not our loss of privacy.
I understand your point is that our loss of privacy didn’t lead to arrests or in these instances, but there has almost certainly been arrests in other instances, and we’d be losing sight of the bigger picture if we deluded ourselves into believing oppressive governments, companies, billionaires, etc.. weren’t already heavily using mined data to counter dissidence movements in more ways than just arrests.
Governments responded to the Arab spring by taking social media much more seriously. There are a lot of ways to use social media to suppress and discourage dissent, outside of arrests; it's a very powerful counterintelligence tool.
