He's saying that when a person don't like something, the recent trend is to just label it as "inciting violence". He then adds onto that by saying the idea of "silence is violence" means that anyone who does not speak out against the disliked thing is inherently guilty of "inciting violence" as well, so lurkers and moderates are not safe from being labeled.

Again, I disagree with what he said. However, accusing his post of threatening violence against everyone with whom he disagrees does kind of support his point.