Trayvon Martin was fatally shot on Feb. 26, four years ago. The unarmed teen's death, in many ways, gave birth to the Black Lives Matter movement, which has reframed the way Americans think about police treatment of people of color.
Martin was not killed by a cop, but by George Zimmerman, a member of the local neighborhood watch who claimed he shot the black 17-year-old in self-defense. A Florida jury acquitted Zimmerman of murder or manslaughter in July 2013. The verdict was unpopular with huge numbers of people. Three of them, Alicia Garza, Patrisse Cullors and Opal Tometi -- all black women, all friends -- reacted by posting #BlackLivesMatter on social media.
How did their hashtag catch fire with Twitter users and become a rallying cry at demonstrations in places like Ferguson, Missouri and New York City, not to mention the name of a powerful network calling for racial justice? A new study from American University's Center for Media and Social Impact examines how social media fueled the biggest push for racial justice that the country has seen in decades.
"Twitter, Facebook and social media platforms are really ground zero for focusing attention," said Charlton McIlwain, a New York University professor and co-author of the study "Beyond the Hashtags: #Ferguson, #BlackLivesMatter and the Online Struggle for Offline Justice," which was published Monday. "Social media was a tool to drive visibility."
#BlackLivesMatter Takes Hold
While the phrase "black lives matter" debuted following Zimmerman's acquittal, it didn't take root until August 2014, when Ferguson police officer Darren Wilson killed Michael Brown, the report found.
Prior to the major protests in the St. Louis suburb, there was barely a mention of the phrase on Twitter. But the researchers found a huge spike in tweets including the phrase and related keywords around that time. On some days, there were almost 2 million tweets using one or more of the dozens of keywords researchers analyzed.
"Seeing tanks and armored vehicles to this degree in the small town of Ferguson was a show of force that’s usually reserved for war," said McIlwain. "It was a wake-up call to a lot of people who said 'Wow, this is really a problem.'"
With daily confrontations between protesters and law enforcement in Ferguson, this was the moment the movement hit its stride.
The Movement Grows
Upswings in Black Lives Matter activity on Twitter coincided, unsurprisingly, with current events.
The initial protests in Ferguson over Michael Brown's death were one such touchstone.
The only burst of digital activity than was larger occurred in November 2014, when a grand jury declined to indict Wilson for Brown's shooting. Tweets surged to around 3.5 million on the busiest day then.
There were distinct upticks on social media when a Staten Island grand jury, in December 2014, declined to indict a policeman for Eric Garner's choking death, and again in April 2015, when Freddie Gray died from a spinal injury incurred while in custody of the Baltimore police.
Not all "Black Lives Matter" tweets are supportive. Conservatives made up a small but vocal minority who at times have been scathingly critical, and journalists often attempt to use the keywords while maintaining a neutral tone.
In between peaks of activity, there were long lulls -- even though there was hardly a drop in controversial examples of police behavior. More than 1,000 people are killed by police each year but only a handful of the actually get heavy attention online and in the news media. One of the toughest questions for researchers to answer was why some fatal shootings sparked national interest while others went unnoticed.
"Few clear patterns emerge among those who are widely and seldom discussed—at both the high and low ends there are cases that span a wide range of ages, locations, and dates, with and without accompanying video evidence," the authors wrote. "The mere presence of articles about police killings on social media was not enough: a critical mass of concerned parties had to decide to aggregate their anger into a movement."
Ferguson Becomes Its Own Hashtag
Even though "Black Lives Matter" is an inclusive term extending beyond any single victim or protest location, it was only the the third-most popular keyword on Twitter from June 2014 through May 2015, the report said.
Ferguson -- with or without a hashtag in front of it -- was by far the most popular. It was mentioned in 21.6 million tweets. There were 9.3 million tweets about Michael Brown, researchers counted. #BlackLives Matter showed up in in the third spot with 4.3 million tweets, and there were just under 4.3 million messages about Eric Garner.
In December 2014, the hashtag #BlackLivesMatter began to get widespread use. As nightly protests flared, the hashtag sometimes appeared in more than 100,000 tweets per day.
As its usage rose, other hashtags associated with complaints about the police died out. Remember #HandsUpDontShoot and #NoJusticeNoPeace? McIlwain said #BlackLivesMatter became dominant because it's durable in many social justice situations, such as decrying municipal courts for dubious fines on residents, many of them African American.
"it’s a very simple principle and it’s not tied to any specific action. While it’s focused on police shooting, it doesn’t only incorporate that," he said. "Something about it has broad resonance."
A Picture's Worth Way More Than 140 Characters
The researchers also charted the most widely shared images. Some included footage of the disputed killings while others showed the victims in their best light, such as Eric Garner with his family, to contrast with police statements emphasizing their criminality.
The most widely shared was one that likened the Ferguson unrest to a confrontation between police and civil rights demonstrators in Alabama from 1960 (pictured above).
A Hashtag Becomes A Movement
The movement has been an opportunity to test the potential of social media to amplify the voices of historically overlooked people. It's had many successes: the women who coined the term also co-founded the Black Lives Matter network, which has dozens of chapters in American cities. They exhibit their power by mobilizing the grassroots for large protests and exerting an influence on the presidential race.
Activists in the movement have gained mainstream influence. Activist DeRay Mckesson's campaign for mayor of Baltimore is getting serious scrutiny. Shaun King has become a widely read, though controversial, columnist covering racial justice for the New York Daily News.
King has openly wondered lately whether the public has already lost interest in police reform. It's too soon to write off the movement, McIlwain said, as he's found that organizing continues during these lulls in social media chatter. It has to -- or the movement will fade.
"Social media is not enough," he said. "If it is the only tool being used by the movement, the chances are that it's not going to sustain itself."