Y esterday, at the anti-Alt-Right rally in Berkeley, I watched groups of masked Antifa members in Black Bloc formation swarm individuals who were apparently antagonizing them, and pummel them with their fists, feet, and flagpoles. When the victims tried to escape, they were run down, and in at least one case, cut off by the Antifa mob and beaten down some more. In the incidents I witnessed, about five or six Antifa members at a time participated in the attacks, while perhaps 50 others stood behind them, forming an impenetrable wall that blocked bystanders from intervening, or documenting the violence on camera. Those people would also help chase the victims when they fled.

In one case, as a crowd of non-Black Bloc protesters yelled at the assailants to let their victim go, an Antifa activist yelled, “He’s a Nazi!” over and over again, justifying the assault. Then, abruptly, maybe after realizing that the victim was not, in fact, a white nationalist, he changed his mantra. “He doesn’t have to be a Nazi!” he now shouted. The suggestion was that even if the victim wasn’t a fascist, he still deserved to be beaten. For what was unclear. Maybe because he supported Trump? Or he objected to Antifa’s tactics? Or refused to do something they ordered him to do? Who knew? The only thing those of us watching from a few yards away could tell was that a man, by himself, was on the ground, with a bloodied face, covering his head with his arms, being kicked and punched by a group of masked people, who were shielded by dozens of their comrades. My guess is that a lot of the Antifa people in the crowd who were passively assisting in the violence, including the guy yelling that he was a Nazi, didn’t know anything more than that, either.

Last week, Mark Bray, a historian of Antifa, said on Trumpcast, Slate’s podcast on all things Trump, that Antifa members are “some of the most caring and compassionate people I’ve met.” I just finished directing a short documentary about the online origins of the Alt Right, for which we interviewed several Antifa members, and I can affirm his depiction. To a person, our interviewees cared deeply about egalitarianism and anti-racism, and spent much of their day-to-day lives either working professionally or volunteering for organizations and in activist groups that fought for the social and economic rights of the disenfranchised. They gave eloquent and persuasive explanations for why fascism must be confronted head-on, with tactics up to and including violence.

But parsing out the nuances of moral justifications for violence in a quiet room somewhere is an entirely different thing than standing in a park with a mask on and a flag in your hand, with hundreds of your comrades, and making snap decisions about whose ass to beat and whose not to. Or whether to back up your comrades when they start beating someone up, when you have no idea how the altercation even began, or who the victim is. Or whether to go online afterwards and claim that everyone who got beat deserved it because they were all Nazis.

What happened in practice in Berkeley yesterday was that anybody who challenged the Black Bloc made themselves a target, whether they were a white supremacist looking to stir shit up (and there were maybe five or six of those in a crowd of thousands), or a liberal who yelled their disapproval at their tactics, or a reporter taking pictures after being commanded to stop. If you pissed someone in the Black Bloc off, and someone came after you, the rest of the bloc followed. Suddenly you were facing a hostile mob, the time for arguing your case expired, literally fearing for your life.

I was at the protest with a film crew, working on a documentary. We were in a public park. It was a big news event, where everybody knew there would be media. Activists in the Black Bloc were concealed by sunglasses and ski masks to protect their identity for exactly this reason. They carried flags and banners, to make themselves a spectacle. Yet for their personal security, many of them decided that it was their right to command photographers not to take their pictures, to physically block them from doing so, and if they persisted, to smash their equipment and assault them. That’s what apparently happened to the guy who the Antifa member kept calling a “Nazi,” until he changed his mind. One of my filmmaking partners and I got pushed around by Antifa, too. We were targets because we had cameras. The only reason we didn’t get administered a beat down is because when we were ordered (not asked) to point our cameras elsewhere, we only pushed our right to film them so far. Had we pushed it a bit farther, we probably would have ended up with some smashed equipment and black eyes.

There was a moment of triumph during the demonstration, before all the violence began, when just after facing what looked like the beginning of a confrontation with the Black Bloc, the police line that surrounded the park retreated, the checkpoints into the park, where police were searching bags for contraband, were taken down, and everybody outside of the perimeter flooded onto the field. Following upon the unambiguous victory over the Alt Right in San Francisco the prior day, it should have been the capstone of the weekend. The Alt Right had surrendered; the people had taken their public space back from both the “fascists” and the police. But it probably hadn’t been an hour before that feeling dissipated entirely. Soon, it was Antifa, instead of the police, who were occupying the park. The rest of the crowd, who many of the masked radicals probably disdained as wimpy, bourgeois liberals, shrank from the violence that had begun to overtake the scene, as well as the yelling and the physical domination and the general sense of schoolyard bullying emanating from the massive Black Bloc. At one point I turned around and all I could see was Antifa. They had spread throughout the park, and everybody else had gone home.

When you criticize Antifa members or their defenders for the tactic of mob violence, the reflexive response is usually something like, “There are literal Nazis marching in the streets, and you’re attacking us over your precious little non-violence principles?” But Antifa doesn’t have a monopoly over concern for what’s happening in this country. They’re no more woke than the squishy liberals who showed up to protest with their signs and their voices and not with their fists. The revulsion to violence on the part of most people on the left, from liberal to radical, is not born of naïveté over the scale of the right-wing threat. It’s the expression of basic moral principle, as well as a pragmatic political understanding that random mob violence by masked vigilantes on the left isn’t going to defeat the Alt Right. In the Bay Area this weekend, the Alt Right was already defeated. All Antifa did was transform that message of people-powered victory into a cascade of headlines bolstering Trump’s “many sides” talking point.

The revulsion to Antifa’s violence is also an indication of the paucity of trust Antifa has established with much of the wider, non-activist world. People want the white nationalist movement smashed into dust; that’s why they’re showing up by the thousands and the tens of thousands to protests against the Alt Right. That doesn’t mean they want to hand leadership over to a subcultural vanguardist movement that barks at them from behind masks and shields and threatens to beat those who disagree with them into submission.

Most Antifa members are anarchists. It was an ironic thing to see these anti-authoritarian, anti-government activists essentially acting as a de facto state on that little quarter acre of lawn, ordering photographers around, deciding who could be in the park and who couldn’t, responding to dissent — even from liberals — with physical confrontation, and dishing out violence on whoever they decided deserved it, whether they were a “Nazi,” a non-compliant liberal protester, or a reporter with a camera. It was a bleak alternative to the far right dystopia we face under Trump. It was much more like the last days of the Occupy movement than like the first. It was dark, it was scary, and it was ugly.