Protesters lie in Harvard Square on Friday evening as part of a “die-in” in reaction to recent deaths of black people across America. (Photo: Marc Levy)

There have been no black people killed by police officers here as there have been recently in Ferguson, Mo., Staten Island, N.Y., Cleveland, or so many other places, but that doesn’t seem to dampen the anger motivating protests and marches against institutionalized U.S. racism over the past few days.

Students at Cambridge Rindge & Latin School walked out of class Monday, joining with protesters from Harvard in Harvard Square. Boston Common saw action Thursday. Tufts’ students’ #IndictAmerica effort Friday went from the Tufts campus at 4:30 p.m. to Davis Square, then off to Porter and Harvard before heading onto other squares, ending on a bridge to Boston.

Each square saw a die-in of 4.5 minutes, reflecting the 4.5 hours Michael Brown lay in the street after being killed in Ferguson, and there was chanting along the way that “Black lives matter,” “Don’t shoot, hands up,” “We can’t breathe” and the like. But aside from one speaker in Davis that called out Democratic leaders such as President Barack Obama and presumptive presidential nominee Hillary Rodham Clinton along with capitalism itself, speeches were in short supply, and the arguments articulated at protests earlier in the week also bordered on the abstract: “The fact that we turn our cheek to this thing every day is obnoxious … we can’t pretend that people aren’t dying” was a plea Monday from Sydney Fisher, the high school’s student body president. Vice mayor Dennis Benzan quoted Martin Luther King Jr.’s “Injustice anywhere is a threat to justice everywhere” – something you say with empathy from a distance.

The CRLS students’ statement to staff before walking out of classes read, in part:

We are walking out in anger because of the lack of opportunity we have had to discuss racism in our school. We are walking out in anger because of the lack of justice served to Michael Brown. We are walking out in anger because of the unfair treatment of black people in America, in Ferguson, in Cambridge.

Protest marchers stride down Massachusetts Avenue from Porter Square to Harvard Square on Friday. (Photos: Marc Levy)

It’s at least a matter of scale. In 2009, black Harvard professor Henry Louis “Skip” Gates Jr. was arrested by a white police sergeant, but the racial context was buried quickly and effectively despite contemporaneous complaints, court cases and settlements and various accounts of race-inspired abuses of police “discretion” from Cambridge residents.

Another chant heard while walking along was “No justice, no peace, no racist police,” and that must have rankled the many officers watching over the protesters as they blocked traffic, and who blocked traffic for protesters as the march flowed slowly but unpredictably, including from southbound lanes on Massachusetts Avenue to the northbound.

One officer gave a crowd estimate of 200 in Davis Square, which seemed low when the march took nearly 1 minute and 50 seconds to cross a small intersection into Cambridge. As the march neared Harvard it lengthened and broadened and took at least twice as long to clear a four-lane intersection of Massachusetts Avenue – yet an officer watching the entire thing pass, when asked how many people were marching, gave a flat, rapid and unconvincing response of “300.” A traffic enforcement officer standing at virtually the same point in the march, though, paused in his work and told whoever he was speaking with on his phone that it seemed like there were “a million” people walking past.

Crowd estimates are tough, but Jeremy Warnick, director of communications and media relations for Cambridge police, gave 1,000 as a reasonable figure for Davis Square – there were that many people committed to the march on its Facebook page – but said later that “Approximately 600 people have been involved in the Cambridge protests.”

The protest had been announced only for Tufts and Davis Square. “We knew the possibility of them coming into Cambridge, and it was something we planned for,” Warnick said. “The timing of this made it challenging – there were a lot of businesses being released at the end of the week.”

For whatever reason, there were plenty of people of color watching Friday’s protest march pass by, while the faces of people of color who were marching were surrounded and outnumbered by white allies. That didn’t go missed by watchers, either white or black.

“I’m calling bullshit on all these lame, attention-seeking, traffic-blocking, disingenuous, privileged, WHITE protesters baiting cops (a lot them black cops),” said Roger Nicholson, a former Cambridge resident and current Somervillian who has been in the center of several media dustups, in a Facebook status update. “Go back to your suburban lives. You are all full of shit.” Nicholson is white.

And as the march headed down Elm Street out of Davis, a black couple heading in the opposite direction had this exchange:

“There’s no black people.”

“Exactly.”

A few blocks later the march took a right turn to pass through a Porter Square shopping plaza to get to Massachusetts Avenue and the second die-in. A second black couple stood watching.

The woman said seeing the march pass by “almost made her cry.” But, no, she didn’t miss the fact there were mostly white faces protesting.

So, the couple was asked, is that a bad thing or a good thing?

“It’s a good thing,” the couple said. “A good thing.”