On Saturday night at around eight, I went into my local subway station with a friend. There was a man lingering behind the turnstile, swaying a little. My friend was wearing a miniskirt and a brightly colored lace bra that was visible underneath her shirt. I was in a short black dress. The man growled. I heard the words “beautiful ladies.” My friend didn’t notice. I kept an eye on him.

She reached into her purse. The man was reaching for something, too. He was loosening his belt buckle, and his hand was roving. I felt panic. Was he … no. But yes—he was about to touch himself. The atmosphere was airless, sour. I formulated indignant phrases in my head—“What the hell do you think you’re doing?” “What you’re doing is disgusting”—but the words stuck in my throat like a wad of gum. I worried for my safety: if I confronted him, perhaps I would anger him, and he’d come charging through the turnstile. But, more important, I worried that I was making something out of nothing—that I was imagining this, or that he was drunk or mentally ill, and that calling him out would be needlessly humiliating to him.

I ushered my friend down to the platform. I wondered if he would still be there when I returned alone, late at night, when the station would be desolate, and started charting another route home. The experience of feeling simultaneously threatened and unable to speak, of feeling as if I would be persecuting this man who was committing a sexual impropriety were I to pipe up and tell him to knock it off, was unsettlingly familiar.

This was still fresh in my mind as I scrolled through a series of tweets about sexual harassment, rape, and misogyny, categorized under the hashtag #YesAllWomen. It was started after Elliot Rodger, a twenty-two-year-old man, went on a shooting spree on Isla Vista, near the University of California Santa Barbara, killing six people before committing suicide. In the weeks leading up to the killings, Rodger posted a series of angry, bathetic YouTube videos and a hundred-and-thirty-seven-page autobiographical “manifesto,” declaring his hatred of all women for the rejection and disdain he claims they dealt him throughout his life. Rodger had a pointillist, obsessive memory, and he detailed everything from the food at his ninth birthday party to the names of the kids he played hacky-sack with. Even as a child, he was acutely attuned to power hierarchies and social slights, and he had a peculiar fixation on houses and real estate.

The first half of the manifesto is lucid and reflective—we see glimmers of a happy boyhood and an affectionate, curious personality—which makes his spewings of misogyny and hatred in the second half even more chilling. He wanted to abolish sex, thereby equalizing men and ridding society of women’s manipulative and bestial natures, and to lock women in concentration camps so they would die out. (“I would have an enormous tower built just for myself, where I can oversee the entire concentration camp and gleefully watch them all die,” he wrote. “If I can’t have them, no one will, I imagine thinking to myself as I oversee this. Women represent everything that is unfair in this world, and in order to make this world a fair place, women must be eradicated.”) His idea was to imprison a few select women in a lab, where they would be artificially inseminated to propagate the species.

Rodger’s fantasies are so patently strange and so extreme that they’re easy to dismiss as simply crazy. But, reading his manifesto, you can make out, through the distortions of his raging mind, the outlines of mainstream American cultural values: Beauty and strength are rewarded. Women are prizes to be won, reflections of a man’s social capital. Wealth, a large house, and fame are the highest attainments. The lonely and the poor are invisible. Rodger was crazier and more violent than most people, but his beliefs are on a continuum with misogynistic, class-based ideas that are held by many.

And that is why #YesAllWomen is moving and needed. Elliot Rodger earned the fame and infamy he wished for through his act of violence, and now everyone can read about his grotesque ideas. #YesAllWomen offers a counter-testimony, demonstrating that Rodger’s hate of women grew out of attitudes that are all around us. Perhaps more subtly, it suggests that he was influenced by a predominant cultural ethos that rewards sexual aggression, power, and wealth, and that reinforces traditional alpha masculinity and submissive femininity. (This line of thought is not intended in any way to make excuses for Rodger’s murderousness, but to try to imagine him as part of the same social world we all live in and not as simply a monster.) The thread has produced over a million tweets, and they are by turns moving, enraging, astute, sorrowful, and terrifying. Even though most of the tweets do not directly mourn the people Rodger killed, the tweets accumulate into a kind of memorial, a stern demand for a more just society. Here are just a few examples:

YesAllWomen because ‘I have a boyfriend’ is more effective than ‘I’m not interested’—men respect other men more than my right to say no Because I’ve already rehearsed “Take whatever you want, just don’t hurt me.” #YesAllWomen YesAllWomen because every time I try to say that I want gender equality I have to explain that I don’t hate men. Men’s greatest fear is that women will laugh at them, while women’s greatest fear is that men will kill them. -Margaret Atwood #YesAllWomen Because in about 30 states, rapists whose victims choose to keep the baby can get parental rights, like weekend visitation. WTF #YesAllWomen yesallwomen because apparently the clothes I wear is a more valid form of consent than the words I say I repeat: the fact that there are male victims isn’t proof it’s not misogyny. It’s evidence that misogyny hurts men too. #YesAllWomen

Last night, emboldened by the sense of safety created by a mass of voices speaking of their private fears in a public forum, I added my own:

Because if I know I will be out til after dark, I start planning my route home hours, even days, beforehand #yesallwomen

There is something about the fact that Twitter is primarily designed for speech—for short, strong, declarative utterance—that makes it an especially powerful vehicle for activism, a place of liberation. Reading #YesAllWomen, and participating in it, is the opposite of warily watching a man masturbate and being unable to confront him with language. #YesAllWomen is the vibrant revenge of women who have been gagged and silenced.

Photograph: AP Photo/Jae C. Hong