About a decade ago, when I looked very young (but was wearing a business suit), a GA pointedly looked me up and down and then announced loudly "YOU couldn't POSSIBLY be in FC" when I tried to board with my row. (I'm white.) I said something like "hey, you idiot, before you insult me, please bother to look at my boarding pass and especially look at the price of my ticket" (paper ticket days and I'm not sure how clearly status showed on boarding passes then). I then filed a complaint with the purser by demanding a complaint form upon boarding. My reaction could get one kicked off the plane in today's climate.