On what traditionally has been considered a day of service – or, for many, just a day off work – Martin Luther King Jr. Day is, for many, a day of protest.

Marches, sit-ins and other forms of direct-action were staged in more than a dozen cities, and organizers say that hundreds – perhaps thousands – of combined participants were expected to gather under the banner of the Black Lives Protests that have in recent months diverted traffic, stormed city halls and police stations, and sent chants for justice into the air in as many as three dozen American cities.

“We are very aware of history, and we build on it,” said Charlene Carruthers, national coordinator of the Black Youth Project 100. “Today is about reclaiming what MLK Day means. His work and his image has been sanitized by people who are interested in maintaining the current system of oppression.”