I've seen bottles of alcohol passed around doing talks and heard more than a few really off color jokes about criminal sex acts and such. Vegas waitresses have seen it all also but there was over the top behavior.
We're in a victim dominant culture now, "it's not you or what you've done, you're just a victim of evil or something" but at more than a few Def Cons and more than a few times, it was really uncomfortable to be there and see some of the stuff that was happening.
Worst case scenario is usually they tell people to disperse, but otherwise, they always seemed to laugh when they saw shenanigans (except for people fucking with Casino machines, thats a fast way to make them mad)
For example, the ATMs on casino floors are probably some of the most secure in the nation during the con. Harassment is also taken actually seriously.
I quit going after 7. It seemed like they partying had vastly I overtaken any actual technical content. I don't drink and I'm not super social, so it just seemed like it wasn't "for me" anymore.
Edit: It has probably changed in the intervening years but every time I looked into it it seemed like more spectacle than tech. DerbyCon filled the niche for me for a few years but then it got impossible to get tickets for and imploded. (I know there's a lot of backstory about DerbyCon that I don't know, too. For me it was just a fun way to feel a little of the DefCon 3 vibes again.)
DEF CON is a hell of a party, and I hope to go this year, but the attendees are a force to be reckoned with. Even I ended up fucking up a homemade badge, and tossing a failing lithium battery into the trash in the middle of a casino, only to learn later I created a trash fire, so I know firsthand that we're a problematic bunch.
Also, I was a 17 year old girl at the time, and I felt sexually threatened several times during the event. That is the only place I have visited where I would make a statement of that nature.