Reverend Martin Luther King Jr's 1963 'I have a dream' speech on the steps of the Lincoln Memorial in Washington was a defining moment of the 20th century.
His message of equality and fairness inspired generations of people across the world - but also put him at the centre of the FBI's surveillance operations.
Attorney-General at the time Robert F. Kennedy approved a wiretap and hidden microphone operation that bugged many of King's conversations from 1963 until his assassination in 1968.
William Sullivan, then head of the FBI’s domestic intelligence division, wrote in a top-secret memo at the time:
Personally, I believe in the light of King’s powerful, demagogic speech that he stands head and shoulders over all other Negro leaders put together when it comes to influencing great masses.
We must mark him now, if we have not done so before, as the most dangerous Negro of the future in this Nation from the standpoint of communism, the Negro and national security.
The operation, which was not approved by a court or subject to any investigative oversight, was initially justified to try and prove King's suspected links to Communism.
Thank goodness unsupervised surveillance like that doesn't happen anymore, eh?