Studies seem to show they make everything worse for the cause; politicians distance themselves from causes, public make emotional associations which are hard to break, etc.

Certainly the affect in conversation is obvious, people see attacks on art or blocking roads, etc as anti-social behavior and this locks their brain into thinking of them as a socially destructive force which of course taints their thinking of the cause.

I’ve attended lectures on it at climate protest events, how those tactics can be useful for situations no one is talking about but harmful to well known things - but there were very few people interested, the reality is hard work and learning isn’t fun. Playing hero and living in a self agrandizing fantasy however is fun, especially when you can use it to boost your socials, justify immorality, and all the other things people use religion or extreme politics for.