While the events described are awful, it's important to recognize that the assault type occurrences are very rare events.
yes it happened to 30% of the respondents, but that is over 25 years of (in many cases) more than once event per year.
some of the comments indicate that people think that opensource events are 'Animal House' or 'Revenge of the Nerds' type of events. That is _far_ from the case. While there are some events that I would be leery of going to (Defcon for example), almost all of them are very well run, with well behaved people attending them. Overall I would rate opensource events where people are there because they want to be to be more well behaved, and far more productive than the vast majority of industry events (in any industry) where people are there on expense accounts becuase their company has to have a representive there and that person got picked.
yes, it's common to have a beer BOF (or whiskey, or brandy, or.. ) but it's also common to have a Gay and Lesbian BOF. remember that BOFs are 'birds of a feather', after hours events. If you go to one, you are going because you share interests with the other people there and have an interest in the BOF topic