I'm not so naive to say that sexism doesn't exist in our industry, because it clearly does, but I would say that the vast majority of people would neither encourage or stand for any sort of sexism, whether overt or not.
I think it is tempting to create a link between the stereotypical 'geek' - who is a guy that lives in his mom's basement and never meets women - and the sort of overt sexism and abuse as described in this article, but that is dangerous. That stereotype no longer exists, if it ever did, and there will always be men, from whatever industry or walk of life, who view women as objects and not equals. We need to work on this attitude in every walk of life, not just in the tech world.
But because the industry is so female light a (relatively speaking) large proportion of the women in it have been propositioned or assaulted by the more forward members of the group.
But if the people at these conferences aren't "stereotypical geeks" then who are they?