Yes.
We may be seen as less of a threat, or as Pete pointed out, more of a target because we are seen as "easy" either to control, harm, intimidate, whatever.
That may not make it necessarily so (obviously)

but it's something to consider.
Another thing that made me think of this was yesterday at the mall.
My husband and I were in the food court. He was getting some food for us while I was on the other side of the court getting one of my favorite smoothies. For all intensive purposes, I looked like I was there by myself. While waiting for my smoothie to be made I noticed two guys, just standing around in a heavy traffic area and particularly "noticing" women who seemed to be alone. They took a long hard look at me, talked a bit amongst themselves, then an Asian girl in a black suite crossed between us and they studied her as she walked, talked amongst themselves some more and then promptly took after her (or at least in the same direction).
Now, I have no idea what their intent was, nor am I assuming that they were out to rape or attack or anything. For all intensive purposes they were probably two guys just having fun day-dreaming about girls in a mall. But there was always that "what if." What if they were out to stalk a girl that day, they certainly payed far closer attention to girls who seemed to be alone than anything else. They could easily assume that with their combined strength (the fact that there were two of them) they could subdue a girl. Even if they were just muggers, they might even assume that going after a girl may be easier than going after a guy, and, in my case, had they tried anything, they would probably not have expected getting a gun pulled on them.
Like Pete mentioned, they may target women because they seem like easier target, but that would also lead them to miscalculate what they can't see.
(P.S. Good to see another gal around

)