https://www.politico.com/magazine/st...writers-117512the disclosed files reveal that the FBI prepared preventive arrests of most of the names dropped above, and altogether more than half of the black authors stalked in its archive. Twenty-seven of 51, accused of communism and related extremisms, were caught in the invisible dragnet of the agency’s “Custodial Detention” index and its successors—hot lists of pre-captives “whose presence at liberty in this country in time of war or national emergency,” Hoover resolved in 1939, “would be dangerous to the public peace and the safety of the United States Government.”