The peacefulness of a protest has nothing to do with the political message. Not every concept is about your political bottom line. Friend and foe alike can engage in peaceful and violent protests.
A "violent protest" is a clear concept that means something. You can very easily imagine a peaceful protester with the most awful things written on their sign. And you can imagine the most violent rioters being inspired by the greatest message.
>>wildmu+(OP)
A sign with "Kill All The Jews" is a violent protest, even if they're doing nothing but standing there. Advocating violence is not peaceful, even if the individual is only saying it.