Meh, those aren't as well-defined as you think they are. Variously, market-dominant minorities have been labelled as "oppressors" throughout history, and "we can be as immoral as we want as long as the victims deserve it" has been cover for all sorts of horrible shit. You can do whatever you want under the aegis of "fighting the power" if you just define "the power" as the people you wanted to be vicious to anyway. It takes a pretty simple-minded view of the world to think that a one-dimensional oppressors/oppressed view of the world is anywhere close to reality, instead of just being convenient cover that can be targeted at pretty much anyone, so shitty people can be regressive and sexist and racist while sitting on their high horse.