May Day Protesters Hit the Streets in Oakland, San Francisco

Update, 5:25 p.m.: San Francisco's big May Day march is well under way. The San Francisco Chronicle's Kale Williams says the march -- which began at City Hall and has been heading up Mission Street -- is several blocks long. The destination: 24th and Mission.

Update, 2:10 p.m.: The rally/march/rally featuring Port of Oakland workers and community members protesting police violence is continuing at Oakland City Hall early Friday afternoon. There's a crowd of at least a couple hundred people at Frank Ogawa/Oscar Grant Plaza -- that's an estimate from watching a live stream of the event. The crowd is hearing from speakers, including Occupy Oakland activist Boots Riley and Jeralynn Blueford, mother of Alan Blueford, a teenager shot and killed by Oakland police in 2012.

The City Hall gathering was preceded by a rally outside the Matson shipping company's gates at the Port of Oakland. That demonstration, organized by International Longshore and Warehouse Union members who stayed off the job Friday morning, was followed by a march through West Oakland to City Hall.

“Policemen are not doing what they were hired to do," Janis Smith, a member of ILWU Local 10, told KQED's Devin Katayama. "They’re going overboard. They’re just killing, killing, killing.”

Union member Stacey Rodgers says the longshore workers have a long history of protesting in support of social justice issues.

“When I’m not a union member, not at work I’m still a community member," Rodgers said. "And this effects all of us in the community. Particularly the black and brown communities and the majority of longshoremen are minorities.”

Rodgers noted that close relatives of local ILWU members have died at the hands of police. One of them was Jeremiah Moore,a man shot and killed under questionable circumstancesby Vallejo police in 2012.

His sister, Rebecca Moore, told Katayama: "This is something that all of us together get to stand up against. And I get to speak for my brother’s cause and it kind of gives you hope that there could be some change."

More activity is to come, with activists having called an 8 p.m. gathering at City Hall that will coincide with the monthly First Friday event.

Here's our Storify on the day so far:

Update, 9:45 a.m.: The focus of the day's action in Oakland has shifted from MacArthur BART, scene of an anti-gentrification protest seeking to block tech company buses, to the Port of Oakland, where a good-size crowd has gathered to rally against police violence.

No estimate on the size of the crowd at the port, which includes members of Oakland's International Longshore and Warehouse Union and other labor groups, which will march to Frank Ogawa/Oscar Grant Plaza outside Oakland City Hall.

At MacArthur BART, the planned blockade of tech buses didn't quite happen because most of the buses appear to have arranged to pick up passengers near West Oakland BART and elsewhere.

"The tech buses are symbolic," William Jones, a protester from East Oakland, told KQED's Andrew Stelzer. "It's more than just the techies, but they are a symbol, they're a target because of the attitudes of young, often suburban people moving into a new community, not networking with the older residents, calling the police on them, et cetera."

Fellow demonstrator Jesse Brown said the action was meant to send a message to technology companies.

“While it might seem like, 'Oh, well, you didn't block the buses, it was a failure,' I think it's more important that we be able to communicate to these corporations that evade taxes and do these unpleasant things that we know they’re here and we know where they are and stand," Brown said.

Demonstrators also reacted to Friday morning's news from Baltimore that six police officers have been charged in the death of Freddie Gray, a man who suffered fatal injuries while in custody last month.

“Just arresting six officers or trying six officers won't fix the massive structural problems that happen across the police structure of this country,” Brown said.

“They have to start actual actually reacting and holding officers accountable, or else there's going to be riots across the country. And they know that now,” said a second protester, who identified himself only as Jordan.

And if you're wondering how long Friday's actions will continue: all day and into the night. A gathering has been called for 8 p.m. tonight outside City Hall to coincide with downtown Oakland's First Friday gathering. That promises a long evening of marchers roving neighborhoods near the center of the city.

Original post: Our favorite tweet, so far, on Friday morning's May Day protests in Oakland -- first at MacArthur BART to block tech company employee buses, later at the Port of Oakland to protest police violence.

The MacArthur BART action, the latest focus on the tech shuttles, drew about 50 people as of 8 a.m., KQED's Andrew Stelzer says. It's part of continuing protests against gentrification in the city. We note that the early wave of buses, which head to Google, Facebook, Yahoo! and other Silicon Valley campuses, did not show on schedule. There are reports from the street that the buses made pickups at alternate sites. BART service was not affected.

Here's our Storify, tracking media reports, social and traditional, of the day's activities.

KQED's Devin Katayama and Andrew Stelzer contributed to this report.