In late August, a crowd of thousands — primarily leftists and liberals — cascaded down Martin Luther King Jr. Way in Berkeley, Calif. They were marching on a spattering of right-wingers, Trump supporters and Nazis who were gathering under the mission to say “no to Marxism in America.” At the front of the march were about 100 people dressed in head-to-toe black.

According to many people present, this was the largest so-called black bloc they’d seen. This medley of black-clad anarchists, anti-fascists (known as “antifa” activists) and their fellow travelers was a response to the previous week’s white supremacist rally in Charlottesville, Va. There, protests ended with 19 injured and 32-year-old Heather Heyer killed when James Fields, an admirer of Hitler who demonstrated with white supremacists, drove his car into a crowd.

This mass of solid black descending upon the park in Berkeley, hunting for fascists, was an intimidating aesthetic. That’s by design.

“Cops wear camouflage when they arrest people in city drug raids,” said Ben, a Bay Area activist. “But they’re in a city. It doesn’t help them, but it makes them look more intimidating.” Ben says he has participated in protests since 2000, including Bush/Gore, Occupy Oakland and Black Lives Matter. (The Times agreed to use only his first name because of the threat of harassment, online or otherwise, by activists.) “A group of people all dressed in black can be intimidating,” he said.