...Hoover's comments were widely publicized....
...On November 27, Roy Wilkins was told by Cartha DeLoach that if King wanted "war" the FBI was prepared to engage in one, and the two of them discussed the FBI's "derogatory" material. Wilkins told DeLoach that if the FBI made it public, it could ruin the civil rights movement. Obviously Wilkins reported this back to King, and a number of leaders, including King, agreed to take steps to set up a meeting with the director. Hoover agreed to meet with King on December 1.
According to all accounts, the meeting was exceedingly cordial. Hoover expressed support for the civil rights movement and then turned to what was on his mind criticism of the bureau. The meeting consisted of a long monologue by Hoover on the FBI's efforts to protect civil rights demonstrators, enforce the laws in the South, and prevent terrorism. At the end of the meeting, King and Hoover agreed to a public truce.
Only now do we know how close the FBI came to an all-out confrontation. Unknown to King or SCLC until later, the FBI, at the height of the public controversy, took its most distressing step. It mailed the "tapes" to the SCLC office in Atlanta with a covering letter urging King to commit suicide or face public revelation of the information on the tapes on the eve of the award ceremonies in Sweden. The letter said in part:
King, there is only one thing left for you to do. You know what it is. You have just 34 days in which to do (this exact number has been selected for a specific reason, it has definite practical significance). You are done. There is but one way out for you. You better take it before your filthy fraudulent self is bared to the nation.
It was thirty-four days before the Nobel Peace Prize ceremonies....
http://www.thirdworldtraveler.com/NSA/Vendetta_MLK_LS.html