ON OCTOBER 22, just before dawn, hundreds of people, including many families, gathered and prepared to march toward the Dakota Access pipeline construction site near Standing Rock, North Dakota. Dozens of officers, backed by military trucks, police vans, machine guns, and nonlethal weapons, violently approached the group without warning. In total, more than 140 people were detained in half an hour. It was the largest roundup of protesters since the movement against the pipelines intensified two months ago.