When MIT grad student Steve Mann began wearing a computer and a head-mounted camera every moment of the day in 1981, he wasn’t thinking of Black Lives Matter, racism, or police violence. But Mann, now a professor at the University of Toronto, may have given us the key concept for understanding the role of ubiquitous cameras in documenting police violence against people of color. Thirty-five years ago, Mann began thinking about a future that seems increasingly real?a world in which cameras are ubiquitous and can store and share what they see. Mann believed that his Eyetap system would be helpful in enhancing human capability and memory, allowing complete recall of past events. But he also predicted that it would have powerful social effects as millions of people with connected cameras could collectively hold authorities responsible for their misdeeds.