I and thousands of people poured into Boston Common the night of December 4 to demonstrate outrage over court decisions exonerating police officers who killed Ferguson Missouri's Michael Brown , and New York City's Eric Garner . The crowd of mostly young people flooded the large park at the city's center, overwhelming the annual Christmas tree-lighting ceremony taking place several hundred yards from the State House, which sits atop the park's main summit.
Riots broke out in Ferguson, Missouri last week after twelve jurors — nine of them white — elected not to indict Darren Wilson , the police officer who shot and killed 18-year-old Michael Brown, the black teen whose death triggered many days of mass demonstrations and militarization of police forces in response. Just this week, a grand jury in New York dismissed charges  against police officer Daniel Pantaleo, who choked Eric Garner to death amid an altercation over Garner allegedly selling loose cigarettes without license to do so.
Mobile phone video footage of Garner's killing proves that Garner had begged mercy from the officers, as he repeated over and over again the now viral collective plea “I can't breathe!” Video of the incident was taken by Ramsey Orta, a friend of Garner's who was later indicted on weapons charges .
Communities across the United States have been overcome with shock and anger at the grand jury decisions in both cases. In New York City, Chicago, Philadelphia and Boston this week, demonstrators have brought voice to hashtags like #BlackLivesMatter and #ICantBreathe that have overwhelmed social media since the Ferguson decision came down. And the revival of other classic protest chants that long pre-date the hashtag reminded us that this problem is nothing new:
“Hey-hey! Ho-ho! These racist cops have got to go.”
“No justice, no peace. No racist police.”
In Boston, police arrived in public buses with the words “State Police” where the final destination usually appears. Clad in neon yellow vests and wool hats, officers lined up in row after row, behind the majestic gates that separate the State House from the public park where it sits. Police stood shoulder-to-shoulder on the grand steps of the State House, hands folded in front of them. Four men in suits and long coats stood on the state house balcony, looking down at us. Despite questions and cries of frustration from demonstrators, the police were eerily silent. They must have been instructed not to engage, not to respond.
Protesters then began a determined, freezing cold walking tour of Boston — from major bridges to highway entrances, our band of thousands stopped traffic in many directions, for what had to have been hours.
Drivers texted, talked on their phones, took pictures and video of the crowd passing by. Many waved or honked their horns in support. Some opened their windows to the bitter cold air and held out their gloved hands, exchanging hi-fives with protesters as they walked by. Others scowled and waited for the roads to clear.
— Frederic Thys (@fredthys) December 5, 2014 
We marched across the Charlestown Bridge, performing snippets and soundbites from the brutal incidents of police abuse that triggered our gathering. Again and again throughout the night, thousands of hands, skin of every shade, shot up into the bitter night air and the chant was loud: “Hands up! Don't shoot!” Again and again, demonstrators shouted, “I can't breathe!” Cardboard signs commemorating black people who have been killed by police spanned from Oscar Grant to Rodney King to Amadou Diallo , the Guinean immigrant killed in 1999 by New York police who shot 41 bullets at the 23-year-old reached into his pocket for his wallet.
— Praline Queen (@blowticious) December 4, 2014 
How is it that so many people have lost their lives to become symbols of a systemic crisis, something too big to simply be called a problem, something centuries in the making?
At the foot of Bunker Hill, the site of one of the most important battles of the American revolution , we all lay down in the street before long lines of cars waiting for us to move. Instead of continuing to chant, clap or hold up our hands, we took a long moment of silence. Then, like a flock of birds, each responding to the next, we rose and started walking again.
Ellery Roberts Biddle  is the Global Voices Advocacy Editor and a Berkman Fellow at Harvard University.