Daniel Ellsberg released the Pentagon Papers, a top-secret Pentagon study of US government desicion-making about the Vietnam War.
Senators refused to publish the 7000 pages, so did several other newspapers. Finally the Times published it and Ellsberg went underground for sixteen days before he turned himself in.
The Nixon administration began a campaign against further leaks and against Ellsberg personally. CIA committed burglary of his psychiatrists office to find compromitting information against him. They also illegally wiretapped him.
Ellsberg was taken into custody, believing he would spend the rest of his life in prison. He faced charges under the Espionage Act of 1917 and other charges including theft and conspiracy, carrying a total maximum sentence of 115 years. The judge presiding over the trial was consequently offered directorship of the FBI.
Here you can here him talk:
The 7000 pages showed that the president was lying. We don’t need to read 7000 secret pages to know that the same is happening today with the current president. What is amazing, however, is that this man was willing to go to prison for telling the truth.