Apparently there are a number of Steveosphere regulars who think FeministX is actually Half Sigma. It's funny to think about a pseudonym being accused of posing as a different pseudonym, but FemiX's female lusting is at least on par with that of the average guy. Further, Half Sigma seemed to think the person behind Stuff White People Like would turn out to be an Asian man, so I suppose it is plausible to think he has a predilection for the idea of Asian internet anonymity. Both favor abortion--not just the right to abortion, but abortion itself--and both are quick to criticize Steve Sailer for his presumed affinity for Sarah Palin.
For what it's worth, though, I'm still highly skeptical on account of their interactions here. FemiX reads most or all of what I write--it's apparent on her blog and in my comment communications with her (the favor is returned, although sometimes I'm too late to contribute to the comment thread before it goes cold). Half Sigma has this spot on his blog roll as well, but is only an occasional reader and is usually unfamiliar with data presented to him that I've marshaled in previous posts, whether it backs up or challenges particular assertions he is making. Perhaps when wearing the Half Sigma hat he pretends not to have read what he actually has, but since we're on good terms and I've never mentioned anything that in the remotest way suggested he might be her, if he's pulling it off, his level of ubiquitous meticulousness in separating the two virtual identities is astounding.