The FBI's War against Martin Luther King
From those "radicals" at the ACLU....
As Dr. Kings political power, stature and influence grew, the FBI, under the direction of J. Edgar Hoover, grew increasingly obsessed with King. In turn, they used various tactics in the 50s and 60s to try and discredit him, such as mounting a full-court press to portray him as a Communist provocateur, attempting to disrupt tributes after Dr. King won the Nobel Peace Prize in 1964 and repeatedly bugging his hotel rooms.
The FBI so viewed Dr. King as a threat that they even tried to covertly besmirch his reputation after his assassination, when Congress in 1969 first considered making his birthday a national holiday.
These shameful actions were detailed in a 2002 ACLU report that highlighted one of the sorriest chapters in FBI history, in order to bring attention to the dangers of domestic spying.
His crime was to challenge the laws enforcing segregation and preventing the right to vote, the report said. His crime was to protest the Vietnam war and to denounce policies that did not address widespread poverty in this country.
http://www.aclu.org/blog/national-security/fbis-war-against-dr-king-revisited