And it happens even in "progressive" places.
A few years ago I tried to get into a local "geek breakfast" just for the sake of networking. It was mostly men. There were a few women, but they tended to be peripheral to the "seriously technical" men: recruiters, marketers, wives and significant others. I was there because I wanted to be "technical".
The unofficial manager of the group was the guy who kept the email list. Like many early tech courtiers, he had risen to power by getting a lot of people onto the same email list and keeping the list useful by sending out "insider" announcement of pertinent events. I wanted to be on the list, too. Yet after 6 months of going to the breakfast, I wasn't invited.
Finally, another woman of the tech recruiter/marketer species intervened on my behalf, and I was reluctantly added to the list.
Soon after there was a discussion about why email was "broken". At an appropriate break in the conversation, I started to offer my ideas on the subject - which I had recently given some thought to. But then another guy just started talking over me as if I didn't exist.
I then, very politely, pointed out that he had interrupted and talked over me. And I doubted he would have done that if I had been male.
He stared at me a minute and then went on with whatever he was talking about.
Later, outside, the recruiter/marketer woman took me aside and said I made the list owner guy "uncomfortable", so he was kicking me off the list again. I was being exiled because I had resisted being talked over. Because I had called them on their sexism.
I never went back.
What really irks me is not the list owner or tech guy that talked over me (they were both sexist jerks) - but rather all the people who stood by. There were a lot of people I thought of as "progressive" in that group. Yet none of them defended me or reached out to me after I left.
I guess some would say I didn't try hard enough to "network" in the tech community in my area. But why should I have to fight my way into the profession? If I have the credentials and the abilities, shouldn't I be welcomed and mentored instead?