Yes, it's sexist to be surprised, or even to be delighted, that the Anonymous apparatchik that cracked the odious HBGary Federal,stole its email, revealed its secrets and forced the resignation of its CEO might have been a girl. Especially a 16-year-old girl.
It's not even certain it's true, though Forbes' Parmy Olson interview-by-email of the person who claimed responsibility contains some juicy details.
"Kayla" was one of four Anonymous supporters who broke into HBGary's servers. As the one who posed as current-CEO Greg Hoglund to an IT administrator, you could say she's responsible for all that happened afterward, including the shame and resignation of then-CEO Aaron Barr, who called the lulz down on himself by bragging he could out some of the Anonymii.
Kayla spends hours a day online, keeps her OS on a USB stick, her data on a microSD card and runs everything she does in a virtual machine – all the better to hide what she's doing, or destroy the evidence if she's on the verge of being caught.
She told Olson she could chew up the microSD card for safety.
She started young; her first big hack was against a fellow IRC network user to defend a friend.
Her father supported her early efforts in ways that make her sound more like a promising someday-professional athlete than an elite hacker, but excellence is excellence and requires the same kind of support no matter what the field, I suppose.
What's impressive, besides the list of languages and systems she's learned or cracked, is that she made herself a respected presence on the Anonymous channels, which may not be dominated by sexist, adolescent male attitudes, but are certainly rich with them.
"Kayla" has been paying a lot of attention to Libya lately; if I worked for Moammar Qaddafi, I think I'd be worried.