Extremism for a good cause is fine. Breaking the law is dangerous but not necessarily wrong. If the only "harm" done is to profits/property it's not real harm. I was going to say that as long as no-one is getting hurt or doing things like setting fires it's fine.

But I would absolutely punch someone on the street if it was the only way to get them to stop torturing a stray dog/cat. How does that scale up? I have no idea, honestly. But if no-one is being hurt it's definitely okay.

I think the people who risk their liberty and sometimes their lives like this are very brave. I'm not brave enough to do anything like that but I'm glad there are people out there who will do it.