Legality doesn't make it right. You prove that by fighting it. Nor does the illegality of taking violent action, if necessary, remove responsibility to do so. God will not look down on Germans that knew about the Holocaust and say that they were following the rules and it was ok to let it continue. You know that murders are taking place. You aren't stopping them. Peaceful protest is great when the action you're protesting is peaceful. When the action you're protesting is murder, you're either a coward or you don't really care.
I choose not to fight violence with violence. The argument about "why aren't you doing anything about it" is poor.
The are many ways to tackle issues. People that protest violence of war are never told "why don't you get violent and fight back if you are so against it". They protest.
I choose several different ways to fight the evil of abortion and the death culture. I have participated in interventions, crisis counseling, and protests. I have met several lives that I have been able to help save. Greatest feeling in the world.