@Eorl,
It's possible...
I think also women feel freer to react, at all, whereas men don't want to indicate that they've noticed.
I do get what people are saying about the brand of activists who will haul out a boob and then stare challengingly around -- it feels almost like performance art, like it's meant to get a response, and then it's frustrating when you know that you can't respond/ will get in trouble for responding. (I actually get their perspective too, but that's not my point right now.)
But I still think there is something deeply wrong about how tortuous it was for me to navigate in public with a breastfeeding baby. I tried to do everything right, I had no intention of offending anyone, but my choices were a) put up with extremely uncomfortable and unsanitary conditions to feed my baby, b) stay home until she was weaned, c) let her scream until I got home, however long that may take (and no matter what I was doing when she got hungry), or d) go ahead and feed her as discreetly as possible -- and feel the righteous wrath of onlookers. C'mon, people. Is it really that important? (Daily feeling of righteous wrath for months and months can be rather horrible...) (Well not daily, because some days I would stay inside specifically to avoid it...)