Have you Googled the term? Apart from the first page or so being dominated by that very recent event of the crowd intimidating people and many other people conflating that event with that slogan, you'll find plenty of articles about what it means: that choosing to not speak out about an issue helps support the status quo. In fact, I've generally seen it used to try to persuade people who don't want to support the status quo that staying quiet or trying to "not be political" is in fact supporting the status quo.
I mean that's just fine, and a perfectly fine point to make - and one with which in fact I agree; I have railed against police and prosecutors' offices for years, having been on the ass-end of their horror myself.
But if that's what one means to say, then say that; because the word 'violence' has a specific meaning not captured by "don't support the status quo".
This is a long way of saying I generally don't like slogans :/
I don't think there's a generous way to interpret that expression. Silence is de facto not violence. Violence requires physical action.