Haven't read all this topic but I'd just like to post some of my thoughts for those who might still care about this thread and whatnot... anyways...
1. I think it's pretty ****ing obvious to anyone that there is and has been for pretty much ever a major problem with online gaming and what happens when someone is found out to to be a woman. It's certainly one area where I would have to agree wholeheartedly that there is undeniable sexism and immense harassment almost universally and as shy and paranoid a person as I usually am, I imagine I would feel far far less comfortable playing games online if I were a woman and would almost certainly hide it for fear of the consequences. It must be a rather uncomfortable thing to do and make you a rather paranoid human being as a result by necessity.
Something should be done or something has to change, and I'm not either saying that it's ever or always a good idea to try and make things change by pure force where you maybe still have the problem just masked and swept under the carpet but surely in at least the kind of blatantly harassing cases, banhammers and whatnot are appropriate.
2. Let's not go mad either. There are fine lines here, and I only think such banhammers should be wielded when these things are clearly rather blatant, as mind you of course they often are. I don't think we should have some kind of blanket ban on arguments or negative comments towards people online. It's hard to know where to draw the line though and I think you have to allow some level of banter. Specifically targeting females online in a rather malicious way and clearly trying to make them feel out of place and singled-out should be a reasonably clear thing to discern however, I should think, but realistically I don't think erring on the side of caution is going to cause much harm either and giving people the benefit of the doubt rather than coming down on them like a sack of banhammers. We all know how blatant this kind of thing usually is when it does get going. I don't think there's much fear of this usual kind of online game genuine sexism occurring and staying under the radar by people (presumably rather young) doing it but restraining themselves.
Another thing then: while men can imagine what it might be like to be a female gamer, as you do say, they don't actually know what it's like. It would however, be worth remember, IMHO, that female gamers do not either know what it is like to be a male gamer and the discomforting ultra-caution that might be caused by something like this being implemented over-zealously. You're a female; you'll never need worry about being (mis)interpreted as sexist or that in such a situation you won't be able to explain yourself and be given the benefit of the doubt. A zero-tolerance one-strike policy could be madness if done improperly. Like people have said: is calling someone a ***** going to be sexism? Even when it is clearly not intended that way, or where anyone would reasonable give it the benefit of the doubt? Then what about calling someone a dick? There's no way, even if female equivalents were automatically deemed sexist, that would ever be deemed sexist.
These things need to be done thoughtfully and without as much knee-jerking as we can help. Online gaming, as anyone can see, is generally often a rather intimidating and hostile place for women in so many ways, but there's no need for one to get tunnel-vision either and lose sight of the big picture and make it less comfortable for other people either if it can at all be helped.
Bottom line: NO NEED FOR US TO TURN AGAINST EACH OTHER NOW, CHAPS o_q. We have enough common enemies outside of gaming as it is...
EDIT: Also, good thing nobody cares about Halo 4 anyway, mirite? ^_^