BART police in riot gear, protesters in bandannas, reporters with iPads, and citizen journalists with Flip cameras, along with enervated commuters, all gathered at Powell Street Station in San Francisco Thursday afternoon, in a protest that started out almost festive but ended chaotically.

The light perfume that typically fills the Powell Street Station, the transit link to the Westfield San Francisco Centre and several major San Francisco retailers, was a contrast to those who arrived there Thursday, all very different and present for different reasons.

As of about 4:45 p.m., the station almost had a convivial atmosphere: four young students had assembled by the Powell Street entrance with their instruments, playing upbeat music with their violins and cellos. Dozens of people crowded around the ticket dispensers and front entrance, minding their own business and chatting with each other. Police lined the edges of the station, their batons lightly pressed against their hips.

Over the next few minutes, however, the mood quickly changed as demonstrators began to speak out. The protest was loud and energizing.

“It’s important to speak out against injustice,” said Loba, a Bay Area resident and protester who was dressed with a navy bandana around her nose and mouth. She declined to give her last name, saying that she wore the bandanna because she did not want to be identified in photos. Several other protesters were dressed similarly; one had a bright green bandana wrapped around his head like a turban.

Callie Maidhof, the chief organizer of the BART protests, said she was excited about a new tactic for Thursday’s protest. “We are stationed in front of the fare gates, but leaving the flood gates open for commuters to ride for free,” she said. Police made sure that those heading down the escalators to the train platform had paid by breaking up groups of protesters standing at the turnstiles.