This is a direct and clear example of bias which made it easy to flag the ML algorithm. But what about ML algorithms that are inducing benefits to groups in less obvious contexts? What about groups that are not so easily identified as being protected classes by simple, human-understandable model features? What about cases where the features are just merely correlated with a subpopulation of a protected class?

If we're being honest, a system only needs to be in a decision-making capacity for discriminatory behavior to be scrutinized, since in many cases human operators will not be able to identify the specific features being used to make decisions about people -- the features could be highly correlated with some subpopulation of protected class. If you take that to be true, the question reduces onto what decision-making roles ML algorithms have that could be discriminatory, and it's hard to argue this is not a massive part of their current and expected roles.

I think this is going to be a long, winding ethical nightmare that is probably just getting started by human-digestible examples such as these. One can imagine things like this one being looked back on as quaint in the naivety to which we assume we can understand these systems. Where do we draw the line, and how much control do we give up to an optimization function? Surely there is a balance -- how do we categorize and made good decisions around this?

As far as I know, a cohesive ethical framework around this is pretty much non-existent -- the current regime is simply "someone speaks up when something absurdly and overtly bad happens."