To act passively or to not act passively, that is the question.....

This is in response to Bryan's question.Is there any situations in life when you should not act passively towards aggressors? And, If so, when should you not act passively?
In most situations it would be wiser to act passively. Although, there are occasions where acting passively will do nothing for you. Then there are sometimes where you have to make a choice. A good example would be of the movie the Dark Knight. There is a part of the movie where the joker is killing people all over Gotham. By acting passively, Batman enabled the joker to continue killing people. The only productive thing for Batman to do was to come forward and reveal to the joker his true identity. A continuity in passive attitude would have resulted in the deaths of more people. My point here is that, especially when dealing with cereal killers, it is definitely not a good idea to act passively.
Question: Do you think there are people that exist that do things just to test societal norms? If so , why do you think they do this?