Second of two parts

'We have to support the people in Ferguson," said Kashara White, 22. "We can't let them be shot by rubber bullets while we sit here twiddling our thumbs worrying about who got shot next. We have to put our bodies on the line."

White was standing in the streets of Philadelphia on Nov. 25, the day after a grand jury decided not to indict police officer Darren Wilson, who on Aug. 9 fatally shot Michael Brown in Ferguson, Mo.

White took part in a peaceful demonstration in Philadelphia, one organized largely via social media. She was among thousands across the country demonstrating that night - and again on Dec. 1, when people walked out of schools and businesses to protest the decision. Demonstrator Gena Frère-Jones tweeted: "i am honored to be a university of pennsylvania student today," attaching an image of demonstrators lying as if dead in the street. T. Stokes tweeted: "I was getting emotional when we shut down Market St. Never been so proud of my school."

These people, organized via Twitter, Instagram, and Facebook, were putting their bodies where their tweets were. The Ferguson protest movement, four months old and still far from done, joins other long-term socially mediated protests here and in places including Thailand, China, and Mexico.

For the year in social media 2014, the big question is: Are social media as social protest effective? What, if anything, do they accomplish, both for those who demonstrate and for the larger community? Is it all just ephemeral self-indulgence by millions of young folks with smartphones and itchy thumbs - or can they have social impact?

"It's better to have this than not," says Charles Gallagher, chair of the sociology, social work, and criminal justice department at La Salle University. "These demonstrations definitely show the ability of these media to mobilize people, to put pressure on politicians, and to keep issues in the public spotlight."

In May, after a gunman killed seven people in Isla Vista, Calif., leaving behind a raging anti-women screed, the hashtag #YesAllWomen arose, by which women explained that, in their view, every woman's world has a degree of threat a man's world does not have.

Something similar happened in response to the Ray Rice affair in September. The Baltimore Ravens running back was suspended after videos went viral showing him knocking out his then-fiancée, now wife, Janay Rice. (His suspension has now been lifted.) A social-media debate on domestic violence erupted, with the hashtag #WhyILeft, in which women explained their decisions to leave abusive relationships, and #WhyIStayed, explaining why they didn't leave. Reading hundreds of these tweets was a lacerating education in what thousands of women's lives have been like.

"The creativity you saw with #YesAllWomen and #WhyILeft you also see with #IfTheyGunnedMeDown," says Mark Lashley, assistant professor of communication at La Salle University, who studies social media. He refers to a Ferguson-related hashtag. African American men, indignant over the "gangsta" photos of Brown all over news TV, juxtaposed "decent" and "gangsta" images of themselves, asking, "If they gunned me down, which image would they use?"

 Fine: You tweet, you post. But is it all just faux-political selfies? As Gallagher puts it, "Do I get a smug sense of self-righteous involvement, or do I get out there and get smart and do something?" Many such campaigns fade out, with little accomplished. How can we even tell if they are "working"?

Researchers have just begun to probe these questions. Some studies suggest that, for the person posting, joining a hashtag campaign can be what social psychologists call "identity management."

"There is a potential for defining yourself," Gallagher says, "for learning more about something you care about, connecting with something bigger."

A 2007 study in the British Journal of Developmental Psychology suggests that young people on social media have a better, expanded sense of self and connection. In a 2012 study by the Pew Research Internet Project, 66 percent of frequent social-media users (about 39 percent of all users) are politically active, posting and sharing stuff they like, encouraging others to vote, and even attending gatherings and activities organized around candidates and causes.

At some points, social media have played strong roles. Ferguson may be one example. Another may be the Arab Spring uprising in Tahrir Square, Cairo, in January 2011. A study by Zeynep Tufekci and Christopher Wilson found that during those protests, which helped force a change in government, social media "were crucial in shaping how citizens made individual decisions about participating in the protests, the logistics of protest, and the likelihood of success." The more you used social media, the more likely you were to join the protests on the first day.

Still, it can be hard to connect tweeting and posting with getting up and doing something. "There's certainly a danger of confusing mere talk with action," says Clive Thompson, author of Smarter Than You Think: How Technology Is Changing Our Minds for the Better. "Does posting or sharing your feelings diminish your desire to get up and do the hard stuff, organize, talk to politicians, take to the streets?"

To be sure, some folks, like Kashara White, Gena Frère-Jones, and T. Stokes, do get up and get busy. This year's marches, demonstrations, and, alas, violence and arrests are in part "results." So are the multimillion-voice conversations we've had this year, on race relations, domestic violence, sexual harassment on campus, government corruption, marriage equality, and voting rights.

Underserved groups have had a seat at that big, big table - and neither government nor legacy media have controlled the story. Patricia Hynes, a Democratic committeewoman from Ferguson, says, "Social media have given the everyday person a voice. People can at least get the raw and authentic idea of what's being done and said, without being edited by mainstream gatekeepers."

This is where Thompson says, "I'm actually, on balance, on the optimistic side. The pace of real change is slow. But talk is powerful in a democracy. And the single, most straightforward benefit of social media is that we now know more of what everyone - including previously underrepresented groups - is thinking and feels, how they see the world. This is the often-messy, typical back-and-forth nature of political change in the United States, and social media have become a potent force for it."

215-854-4406 @jtimpane

Inquirer writer Sofiya Ballin contributed to this article.