If this happened in real life, they would all be stomped on by normal sized terrorists.

I thought the same thing. I kept wondering how much normal-sized security these communities would need 24/7. And how one lunatic driving a bus could destroy an entire community.

I really enjoyed the film and thought Hong Chau was absolutely perfect as Ngoc Lan. She totally embodied the gritty determination of many immigrants. No time for bellyaching, there's work to do!