Late last week, I found myself embroiled in a long online conversation with an acquaintance over my review of the recent film “Straight Outta Compton.” The movie, which charts the rise of controversial rap group N.W.A., is a well-made biographical drama that raises challenging questions. It also, as one might expect given the subject matter, contains a good deal of content that will be off-putting to certain viewers (and is undoubtedly inappropriate for audiences beneath