This trend needs to stop now. I guess this does not happen much in company-based events where such behavior would be grounds for firing or a warning from HR(or a ban from other company events for outsiders.) The open hacker community needs to step up a little and not let things be too casual to a fault. Diversity is very beneficial to the industry and if a speaker has to resort to crass humor to attract or entertain attendees, that doesn't reflect too well on their skills.