To be fair, I don't think he specifies who might have been silenced?
It’s very helpful not being on social media, because that’s where, if someone criticises something you’ve said, it can feel like a pile-on and it can feel bigger than it probably is, which probably discourages people from saying things. Because that’s part of the point, isn’t it, that people are terrorised into not holding opinions – the idea that we can be silenced.