Andy Ngo, a photojournalist and editor at Quillette, landed in the emergency room after a mob of antifa activists attacked him on the streets of Portland during a Saturday afternoon demonstration.

The assailants wore black clothing and masks, and were engaged in a counter-protest against several right-wing groups, including the Proud Boys. Ngo is a well-known chronicler of antifa activity, and has criticized their illiberal tactics on Fox News. He attended the protest in this capacity—as a journalist, covering a notable public event.

According to Ngo, his attacker stole his camera equipment. But video footage recorded by another journalist, The Oregonian‘s Jim Ryan, clearly shows an antifa activist punching Ngo in the face. Others throw milkshakes at him:

Throwing milkshakes at right-wing politicians is a tactic of British progressive activists that recently traveled to this side of the Atlantic. Rep. Matt Gaetz (R–Fla.) was hit with one earlier in June. The tactic has its defenders in mainstream left-of-center media as well: Vox‘s Carlos Maza tweeted “milkshake them all” after a British activist hurled a milkshake at Nigel Farage.

Portland police have claimed that some of the milkshakes thrown by the antifa activists on Saturday contained quick-dry cement. That may or may not be true. What is true is that an antifa mob beat up a journalist—one who is harshly critical of them, to be sure, but who posed no physical threat to them and was only there to document their activities—on a public street. This is indefensible, and yet there are tons of progressive-leaning people currently defending it, or at the very least rationalizing and making light of it.

Antifa, of course, rejects the notion that violence should only be used in response to a physical threat. The group believes that the very existence of far-right people, groups, and ideas is a kind of provocation that justifies violence—against the far-right, and against their enablers. (For more about the ideology, tactics, and goals of the movement, order my new book, Panic Attack; Young Radicals in the Age of Trump, which includes an entire chapter on antifa.)

I have reached out to Ngo for comment and will update this post if I hear back. A disoriented and clearly injured Ngo posted to his Twitter page here.