Ha-ha-only-serious comments like this really bother me.
I understand that people who say "all women in tech know each other" have good intentions, and are often saying it as a way to build community, or to make the important point that backchannels and whisper networks exist.
But there are many, many "women in tech" (ugh, I hate that phrase too, but I'm choosing battles) that the women-in-tech Twitterati don't know, and apparently don't know that they don't know. A lot of those women are older; a lot of them are immigrants; a lot of them work at big, boring, unsexy companies, or in academia; a lot of them aren't on Twitter. The word "tech" in "all women in tech know each other" seems to refer to only a very specific slice of the tech world. Saying that "all women in tech know each other" erases a lot of women, and that frustrates me.