So he convinced me it's an inside job...but:
As to gender of the perpetrator, there were a number of telling signs in the manifestos. The most telling was a statement calling men "scumbags" (for those readers that don't speak American/Canadian English, this is a word that only a woman would ever use to describe men). In a separate section, the perpetrator describes men as cheating dirtbags. I think in any language this would suggest that a woman is speaking.
If that fails to convince you, then this must: In the first manifesto two names of male members were released. In describing one of them the perpetrator states the he "spitefully" joined Ashley Madison the day after Valentine's Day. Anyone who ever had a significant other knows that women rate Valentine's Day higher than Christmas, and men think so little of it that they have to remind each other the day is nearing. To call an act the day after Valentines Day "spiteful", is a thought that would enter few men's minds. If this does not convince you then you need to get out of the house more often.
So apparently no man has ever called a man a scumbag, and also men are unable to grasp that Valentine's Day is considered important by many people in romantic relationships? Those comments make no sense.