In Enemies: A History of the FBI, author Tim Weiner used recently declassified intelligence files to write a comprehensive history of the FBI...
Weiner said that Hoover disregarded privacy protections mandated by the constitution in order to obstruct the activities of Dr. Martin Luther King Jr. He ordered the FBI to bug King’s bedroom and repeatedly blackmailed the civil rights leader.
"When it came down to bugging bedrooms, you had to be careful not to get caught, but there wasn't anything to stop him," Weiner said. "He decided up to a point ... where the boundaries of the law [were] when it came to black bag jobs, break-ins, bugging, surveillance, the constitutionality of gathering secret intelligence on America's enemies — both real and imagined." (more)