The teenage girls I work with in an institutional kitchen use this word to refer to something excellent. "This cheese cake is bangin'," for example. To "bang" is to fuck, as in "gang bang." If this seems to embody contemporary vulgarity, let's not forget that the word "to rock" also started out as slang for sexual intercourse. And that was 50 or more years ago. Still, I do cringe a bit when I think about the cheesecake, and then recall the still-fresh origins of this word. "Bang" is harsher, I think, than "rock," which can be done gently, after all. Also it seems to me that "bang" carries more intonation of coercion (rape) than "rock," although I don't know the history of "rock."
Under a regime of time that is fully controlled by the market, one cannot be surprised that the search for adjectives that register on the consciousness of other people turns toward bodily sex and violence. So really what such words say to me is not "chaos" or "loss of morality" so much as "stasis" and "frustrated longings for chaos."