Once again, as I said in another thread, this is a case of it's not legally wrong but morally and/or ethically wrong, so you can't do a thing.
People these days don't have much honour or integrity, so calling them out on the practice is likely to result in a shoulder shrug or you simply getting slagged back (particularly, to mind your own business).
Some other people, particularly US-based ones (including many FF types), see it as just a bit more revenge against the airlines since the latter are so good at screwing us over all the time with unfair conditions, one-sided contracts and crying poor despite mega profits and cost cutting.