There’s a classic theory in communication science by the German researcher Elisabeth Noelle-Neumann called the “spiral of silence”[1]. It basically says that people have an idea of the general public opinion on a topic, and in case their own opinion differs too much, they will stay silent in order not to be excluded from the group. This was classically seen with the negative result that the publicly acceptable opinion may not be the same as the majority opinion, as more and more people stay silent in a kind of spiral.
What we’re seeing today in online spaces is the possibility of people connecting online, forming their own bubbles of people with their own spirals – it has become much easier to sidestep the “general” spiral of silence.