On August 9, 2014, the Ferguson, Missouri-based rapper Thee Pharoah took a picture of police officer Darren Wilson standing over the lifeless body of Michael Brown and posted it on Twitter. The image—of Brown’s killer looking on as the body lay uncovered in the street for hours—would be tweeted 41,618 times, galvanizing a national movement to end police brutality directed at unarmed black citizens.

That night was a turning point for the Black Lives Matter cause in many ways—not least in garnering expressions of grief and anger that would soon find collective voice through a set of hashtags known across the globe. Activists Alicia Garza, Patrisse Cullors, and Opal Tometi are credited with having first used #BlackLivesMatter after George Zimmerman was acquitted for the murder of Trayvon Martin in July 2013, but it didn’t see widespread use until it was employed 52,288 times in the weeks after Brown’s death. On November 24, the day of Wilson’s non-indictment for Brown’s killing, it appeared in 103,319 tweets—90% of which were posted between the hours of 8:00 pm, when the decision was announced, and midnight. An image that juxtaposed a photograph of police forcefully confronting black protestors in Ferguson with an eerily similar one from the 1960s was tweeted 46,506 times.

These are among the findings by Steinhardt media, culture, and communications professor Charlton McIlwain and colleagues Deen Freelon and Meredith D. Clark, who combed through 40,815,975 tweets by 4,435,217 users—from June 1, 2014, just before Eric Garner was killed on Staten Island, to May 31, 2015, just after Freddie Gray’s death in Baltimore—to trace the role Twitter played in shaping the national conversation around racialized police violence. In the report “Beyond the Hashtags: #Ferguson, #Blacklivesmatter, and the online struggle for justice,” the researchers tracked 45 keywords (including the hashtagged names of 20 victims) to reveal how Twitter became an essential tool for activists in shaping the narrative on local police cases and protests. Their findings offer a counterpoint to previous arguments that social media activism only makes participants feel like they’re contributing, when they are actually doing little to further the cause out in the “real” world. (Malcomb Gladwell, writing for The New Yorker in 2010, famously declared that the revolution would not be tweeted.)

In their study, the researchers identify six communities who consistently engaged with the issue online during the period they studied: Black Lives Matter activists, the hacktivist collective Anonymous, black entertainers who voiced their opinions on police killings, conservatives who largely opposed the protestors, mainstream news outlets, and “Young Black Twitter.” Activists’ tweets were consistently among the most shared, except for brief periods when mainstream news outlets covering protests (many of which also drew on activists’ firsthand accounts) dominated.

Perhaps most significantly, the activists succeeded in keeping the conversation going between periods of coverage by major news organizations, tracing an arc between incidents that might otherwise have been treated as isolated news items. There were surprises, too, in how conservatives who opposed Ferguson protestors admitted police brutality occurred in the Eric Garner and Walter Scott (in Charleston) cases, and in how Young Black Twitter, a youthful community that generally eschews politics in favor of jokes and pop culture references, came to engage with serious news. They also found that, curiously, although the Black Lives Matter organization was founded by three women, only one female activist on Twitter (Johnetta Elzie, or @Nettaaaaaaaa) was among the 10 most referenced users.

NYU Stories checked in with McIlwain to talk about 21st-century activism and how Twitter shapes the news.

photo: headshot of professor Charlton McIlwain

There’s been much debate over the effectiveness of the social media components of movements such as the Arab Spring or Occupy Wall Street. How did Black Lives Matter differ?
Black Lives Matter has focused itself, very deliberately I think, on a single issue: the U.S. criminal justice system and its injustices and disparities. In doing that I think they’ve made it easier for people to connect with the movement, particularly online.

It’s not one of those things that can sort of be everything to everyone. I think because of that it has drawn a very specific audience and has had the kind of longevity that we don’t see in those other movements. It runs counter to Gladwell's assumptions around digital activism being kind of a short-term and ephemeral. For me, the most significant takeaway is that with this report we were able to demonstrate how social media was used in the ways people ideally thought of it when it was first available: You have a group of people whose voices are not typically heard, but with social media their voices are not only amplified, but really driving how we're framing discussions about this issue.

Of all the hashtags you tracked, #Ferguson got by far the most use, followed by #MichaelBrown, and then #BlackLivesMatter in third. Why did the movement seem to coalesce around the Michael Brown case?
I think that there was something different about Ferguson—different when we look at Michael Brown compared to Trayvon Martin, or any of the others that have come since. There was a clear and vivid interaction between a black youth—whom activists frame as an innocent victim—and the state, as represented by the police. I think the circumstances of those first few hours of the shooting had a lot to do with it. Brown’s body lay on the ground, in the street, for hours at a time. That was one of the things that got people out into the street in the first place, and got them talking on Twitter. Then Ferguson had longevity because of what happened afterward—the protests. The imagery, the video, the photos that were coming out of there were widely displayed, and seemed to show a scene that we are not used to seeing: a high level of militarization and police force generated to combat those protestors and other members of that small black community. I think it was a moment where the country as a whole looked and said, “This doesn’t look quite like what I know America to be.”

Did it surprise you to see conservatives persistently engaging with Black Lives Matter activists online, even if just to disagree?
This was an interesting focal point for me because it’s something you rarely see. In much of my other work looking at political polarization particularly amongst media viewership and readership, things are very siloed: conservatives read conservative stuff, liberals read liberal stuff, and the paths do not cross often or at all. I think it was interesting and important that you had that conservative node connected to this all the way though. On the one hand I think it helps to keep Black Lives Matter from being pegged as a leftist movement that exists without any critical response to it. The principles of democracy more widely require that—the kind of back-and-fourth and engagement across ideological lines that we rarely see. And there was a moment for conservatives to have a rare reality check in seeing someone like Eric Garner or even Walter Scott and saying, “Yeah, probably something wasn’t quite right in this case, and something should be done.”

Were the conservatives and the activists actually talking to each other, or just talking about the same thing at the same time?
It’s hard to say. My guess would be that there is not a lot of talking directly to each other. But I think it is significant that they are at least in the same conversation. There is a degree of influence where, if not necessarily talking back to the conservative publications, activists on Twitter are reacting to responses from the conservative right. And so when folks in Ferguson begin to really frame Michael Brown as a victim, part of that persistence comes as a reaction to conservative engagement that really went out of its was to paint him as a hoodlum, a gang member, and so forth. So I think they're reacting to each other, if not directly speaking to each other. And that, too, is very rare—having these two groups talking about the same thing, and then feeding off of each other in what they're expressing and how they're framing it.

You found that posts about the logistics of protest—details about when and where to physically show up—were not among the most retweeted, meaning that the primary role of social media in this movement hasn’t necessarily been to get people to the streets.
We are getting past a day when bodies in the street are the only, or even the preferred, show of activism. If we say, “nothing is going on if I don’t see bodies in the street” or “something is happening, but only to the degree that I see folks holding signs outside,” we miss a lot of what is actually important. One thing that the report puts front and center is something that we've always known as a crucial hallmark of social movements: consistent attention. What has been typical across racial justice causes over the past 30 or 40 years of activism is that there’s some incident, we talk about it for a day or two, and then it’s gone and we don’t talk about it again until something else happens. It follows the traditional news media cycle. This report shows that Black Lives Matter stands out in how much it demanded attention on this particular topic over a period of time.

Is there a comparison to be made with how 1960s activists used television to focus attention on civil rights issues?
Yes. The medium has changed. Folks in the ’60s were able to orchestrate what was necessary then to capture the dominant media at that time—which was really television and to a certain degree radio. Protests and being out in the streets manipulated and exploited the visual medium that dominated the time. Today, we still have a dominant visual media, but we have this online media as well. Both can work in tandem with each other in a way that previous generations did not have access to. So, one has to give credit to a group of people who are able to manipulate today's tools to do the same thing that their grandparents did 40 years ago. They deserve a lot of credit and praise, not only for their passion and engagement, but their ability to engage and master the new media that is able to push this cause.

You argue that there was an advantage to Black Lives Matter’s online network being relatively diffuse, without strong ties between the people and websites involved. Why is that?
A while back Mark Granovetter popularized the idea of what he calls “the strength of weak ties.” His point was that we tend to think of strong relationships as a measure of strength and endurance and so forth, but weak ties also serve important purposes in certain circumstances. This is one of them—the proliferation and circulation of information. Say we've got five people in a room, and we each all know each other, but very few of us know anyone outside of our group. When we get new information, it circulates very quickly among our group and we all know what’s happening in a matter of seconds, but the conversation ends there because there’s no pathway beyond that group. So, particularly for the spread of information, weak ties are preferable because they enlarge the universe in which that information can travel. That’s what many people see as the value of the social web—because it’s made up of weak ties, news travels fast. We tend to form relationships with people that we don't really know, and though those relationships are not strong, when there is something to be shared, it is shared in multiple networks that bridge all different kinds of communities.