A march in East Oakland, a civil rights slideshow in Temescal, and a rally in San Francisco's Castro District were just a few of several demonstrations happening over the Bay Area against police violence involving black men and other minorities.
The movement is also to take back MLK's legacy and support nonviolent civil disobedience.
"Until we get justice, there will be no peace," said organizer Yvette Felarca.
In Oakland, a group of around 100 or so marched from the Fruitvale BART station to the Eastmont Police Substation. Four were arrested on the way.
One demonstrator passionately asked police, "How do you not care? Every black man I know has been to jail."
PHOTOS: SF, Oakland protests over MLK holiday weekend
Among the group was Dionne Smith-Downs, whose son was shot and killed by Stockton police when he was just 16. She's traveled to rallies all over the country demanding justice.
"We've been out here traveling from Ferguson to New York, Chicago, all around Oakland, everywhere to spread that we're not going to go anywhere and we're trying to educate mothers to get off the couch and let's do this," she said.
Cadine Williams, sister of O'Shaine Evans who was shot and killed by San Francisco police in October, attends ever rally she can.
"And I'm going to fight for all the stolen lives because this has to end today," Williams said. "This has to stop. No more stolen lives."
In San Francisco, protesters blocked traffic at 18th and Castro. A group called Queers and Trans of Color. Organizers say many other LGBT communities have remained silent on the "Black Lives Matter" issue. And their goal is to adopt the campaign's demands as their own.
There were protests on BART Friday morning as well. Demonstrators banged metal spoons on subway pillars and blocked passengers from getting off trains during the morning commute in San Francisco.
VIDEO: BART ridership down Friday due to protest
Protesters say they plan to make it a weekly event that will be held on Fridays. If that happens, BART says it has long-term plans in place. Four years ago, the hacker group Anonymous held weekly protests every Monday on BART.
For full coverage on the protests against police brutality, click here.