In Germany instead of the "silence is violence" slogan people often use the famous Niemöller quote/poem but I have always understand the slogan to express the same sentiment.

First they came for the socialists, and I did not speak out— Because I was not a socialist.

Then they came for the trade unionists, and I did not speak out— Because I was not a trade unionist.

Then they came for the Jews, and I did not speak out— Because I was not a Jew.

Then they came for me—and there was no one left to speak for me.