Visiting Martin Luther King, Jr. at the peak of the civil rights movement, the journalist William Worthy almost sat on a loaded pistol. Just for self-defense, King assured him. One of King's advisors remembered the reverend's home as an arsenal. Like King, many nonviolent activists embraced their constitutional right to self-protection-yet this crucial dimension of the civil rights struggle has been long ignored. In This Nonviolent Stuff'll Get...