Sheesh, she covers up for once and people still aren't happy...
I jest, obviously she could choose a plethora of different items of clothing, but she opted for a Burka, because a Western popular culture icon (who's arguably made a career out of simulating sex acts onstage) deciding to wear a Burqa isn't at all controversial.
That doesn't appear to be the issue on Instagram, however. The issue making itself known in the comments posted centers around whether or not Madonna is aping Lady Gaga. Kind of hilarious if you think about it.
I know the majority of us wish Madonna was entering her Ray of Light phase right about now, but leaving comments like "Could you not copy Gaga, old bat? It's time to get off Instagram and die in a nursing home" might be construed as a bit much.
To quote one JavaJunko: "There's some crazy peeps on this feed...like batshit cray"
