With attention drawn to government surveillance of citizens, some in the media are recalling that this has long been an issue. Columnist Phil Kadner of the Southtown Star, a publication of the Chicago Sun-Times, did so in a recent column, "Do you want security or freedom?":
When Communists were suspected of conspiring to undermine our country, innocent political activists were targeted in the 1930s, 1950s and 1960s. The FBI wiretapped Martin Luther King Jr. because he was campaigning for civil rights.
That was not the reason for King’s wiretap, which was carried out by the FBI after Attorney General Robert F. Kennedy authorized it on October 10, 1963. Kennedy believed that two of King’s associates had ties to the Communist party.
The AG passed that information to his brother the president. In a May 20, 1963 White House meeting on civil rights, President Kennedy said that "King is so hot that it's like Marx coming to the White House" (approximately at 40:55 of the tape.)
The following month, the president met privately with King at the White House. As detailed in Richard Reeves’s book “President Kennedy,” assistant attorney general of the civil rights division Burke Marshall first told King he would have to get rid of the two advisers. “A paid agent of the Soviet Communist apparatus,” he called one. Then Robert Kennedy spoke with King. According to Reeves, “When it was clear that King did not believe either Marshall or Robert Kennedy, the President took over.” Walking in the Rose Garden alone with the civil rights leader, he put a hand on King’s shoulder and said: “They’re Communists, you’ve got to get rid of them.” King didn't, and wiretapping was then authorized by the administration.
So, no, King wasn’t wiretapped “because he was campaigning for civil rights.” At least not according to the Kennedy brothers.