At Yahoo!'s Taiwan Open Hack Day 2009, Yahoo hired female entertainers who danced for attendees and gave male participants at the event lapdances. This is an example of a Sexualized environment at a Technical conference.
The original flickr set documenting the incident was removed shortly after word began to spread -- first the video showing the lapdances, then the entire set (videos and photos).
Images
Pictures from another set on Flickr (courtesy CocaChou): {C 1 {C 2 {C 3 {C 4
These images were made private on or about 21 Oct.
Post with images and links, and critical commentary:Not My Gal, 20 Oct. 2009.
Responses
Simon Willson wrote up a blog post containing screencaps from the now-removed lapdance video. There was considerable reaction on Twitter, including a petition, critical tweets from Caterina Fake (founder of Flickr, which was acquired by Yahoo! in 2005) and Chad Dickerson (CTO of Etsy), and this response from Rasmus Lerdorf (creator of PHP).
The original Yahoo Developer blog recap of the day contained no mention of the dancers, except in the comments where people ask for an explanation. During the event, the official Yahoo Developer Network twitter account tweeted
Hack Girls show perked up all the hackers, now back to their computers http://bit.ly/1zwatP
Some time later, this tweet was deleted, and replaced with
Hack Girls from Y! Taiwan open hack event don't reflect our values. Read the YDN blog post: http://bit.ly/4Civn7
...which links to an apology from Chris Yeh, the head of YDN. (Now deleted: Archive.org copy)
Taiwan Open Hack Day 2008
This is not the first time this has happened -- videos on Youtube (now removed) and photos from 2008 show dancers at Open Hack Day 2008, as alluded to in a FastCompany article and elsewhere.
For example, take a look at this Flickr set.