You are scaring away much more than that.
I just came across an invitation for BugCon 2012.
BugCon is a Mexican conference devoted to computer security — I cannot comment on its level or value because, although it's a topic that has long interested me, I must recognize each day I feel less of an expert, nowadays finding myself at the level of a "sysadmin who tries not to be too dumb for his own job security". Oh, and also because it would be completely off-topic for this post.
If you look at Vendetta's (the main organizer) blog post, it will probably give you the impression that the conference is just an excuse for the afterparty: Lets go see some b00bs! Do you think your fellow female hackers will have any interest in joining a bunch of sex-starved, hormone-infested teenagers who only want to pwn a website and grab more pr0n? Do you think females will feel welcome (or even mildly safe) between you? I would not think so. And I also think you are alienating any professional who might have any interest in joining your community, be it as a member, as a mentor, or whatnot.
I cannot right now do a coherent post on this topic, but I can reference you to what I have seen (and read) over the last almost 10 years, when the issue was first brought up to our attention. I am very glad to see that, at least in the Free Software area, there has been a real change of mindset. I hope you are in time to think about it and rectify.
- Timeline of incidents in Geekfeminism. Note that while it seems we see more as time passes, I am almost sure it's because we are more aware of the problem, not because it occurs more often. I hope I'm not mistaken.
- Debconf ftp-masters talk. Myself a Debian person, my first contact with this problematic was being at the DebConf3 ftp-masters talk — And the discussion and action that followed. This led to the creation of the Debian Women group, one of the most (socially, not technically) influent parts of Debian. Great thanks and admiration to their members, as well as to the (male and female alike) people who have worked to form it and make it heard.
I think Debian Women sparked other similar projects such as GnomeWomen (and there is a list with further projects in there), but I cannot authoritatively say who was there first.
- Planet Fedora up-skirting photo (the original post is still available) showed the communit does no longer tolerate this behaviour. Good!
- The Open Source Boob Project. One of the most childlike attempts at humor that surely alienated many would-be female geeks.
- Another conference season, another dumb sexist, a post by Piers Cawley addressing this issue after attending the CouchDB + Ruby: Perform like a Pr0n star talk. Quoting him, Apparently, the difference between 80s truck salesmen and Matt’s audience is that at least 80s salesmen had the grace to look embarrassed.
- Liz Keogh: "I am not a pr0n star: Avoiding unavoidable associations", a hacker woman that clearly felt offense by the CouchDB Pr0n Star joke, and did a thorough and interesting analysis, extending the effects to your work environment.
- Just Say You're Sorry Already (regarding the same incident on CouchDB+Ruby)
- Richard Stallman's EMACS virgins joke incident. It's sad how it's impossible to get Stallman to acknowledge he can also make mistakes and make feel people insulted.
- [update] And of course, MadameZou mentions the very important 2002 HOWTO: HOWTO encourage women in Linux?
Oh, and not the description of an incident, but a very interesting and thoughtful take on this: [pdf] Interesting analysis by Hannah Wallach on the numbers and motivations of women in Free Software groups. I don't know if Hannah has published this in article form, but many interesting points can be understood by looking at the presentation.
My good friend Vendetta: I don't mean this post (longer than what I originally intended) as a way to say you and the conference you are organizing for the third year (IIRC) already is unprofessional or targetted to pimply teenagers. I know the work you have put in it. I hope you see the points I'm trying to drive — You are of course free to have whatever afterparty you have. But, if as the main organizer, you are giving the images of nice chicks at Hooters more weight and relevance than to the conference itself... you are doing yourself a disservice. I hope you can rectify it, and make BugCon attractive to hacker women as well.