s the 50th anniversary of the 1963 March on Washington approaches, commemorating that historic gathering where Martin Luther King Jr gave his famous "I have a dream" speech, it is important to recall the extent to which King was targeted by the government's domestic spying apparatus. The FBI operation against King is one of the most shameful episodes in the long history of our government's persecution of dissenters.

Fifty years later, Edward Snowden, who is seeking temporary asylum to remain in Russia, took enormous personal risk to expose the global reach of surveillance programs overseen by President Barack Obama. His revelations continue to provoke worldwide condemnation of the US.

In a heavily redacted, classified FBI memo dated 4 January 1956 – just a little more than a month after Rosa Parks was arrested for refusing to give up her seat on a bus to a white passenger – the Mobile, Alabama, FBI office stated that an agent "had been assigned by [redacted] to find out all he could about Reverend Martin L King, colored minister in Montgomery and leader in the bus boycott … to uncover all the derogatory information he could about King."

The FBI at that time was run by its founding director, J Edgar Hoover, who was deploying the vast resources he controlled against any and all perceived critics of the United States. The far-reaching clandestine surveillance, infiltration and disruption operation Hoover ran was dubbed "COINTELPRO", for counterintelligence program.

The FBI's COINTELPRO activities, along with illegal operations by agencies like the CIA, were thoroughly investigated in 1975 by the Church Committee, chaired by the Democratic US senator from Idaho, Frank Church. The Church committee reported that the FBI "conducted a sophisticated vigilante operation aimed squarely at preventing the exercise of first amendment rights of speech and association." Among COINTELPRO's perverse activities was an FBI effort to threaten Martin Luther King Jr with exposure of an alleged extramarital affair, including the suggestion, made by the FBI to King, that he avoid embarrassment by killing himself.

Following the Church committee, Congress imposed serious limitations on the FBI and other agencies, restricting domestic spying. Among the changes was the passage into law of the Foreign Intelligence Surveillance Act (Fisa). Fisa compelled the FBI and others in the government to go to a secret court, the Foreign Intelligence Surveillance Court, in order to engage in domestic wiretapping.

Then came 11 September 2001, and the swift passage of the Patriot Act, granting broad, new powers of surveillance to intelligence agencies, including the FBI. Section 215 of that act is widely criticized, first for allowing the FBI to obtain records of what books people are signing out of the library. But now, more than 10 years later, and thanks to the revelations that have come from the Snowden leaks, we see that the government has used this law to perform dragnet surveillance on all electronic communications, including telephone "metadata", which can be analyzed to reveal intimate details of our lives, legalizing a truly Orwellian system of total surveillance.

In what is considered to be a litmus test of the potential to roll back the Obama administration's domestic spy programs, a bipartisan coalition of libertarian Republicans and progressive Democrats put forth an amendment to the latest defense authorization bill. Justin Amash, a Republican, and John Conyers, a Democrat, both of Michigan, co-sponsored the amendment, which would deny funding to theNSA to collect phone and data records of people who are not subjects of an investigation.

The White House took seriously the potential that its power to spy might get trimmed by Congress. On the eve of the debate on the Amash/Conyers amendment, House members were lobbied by NSA Director General Keith B Alexander, Director of National Intelligence James Clapper, as well as by hawkish members of the congressional intelligence committees.

The amendment was narrowly defeated. A full bill that would similarly shut down the NSA program is currently in committee.

Thanks to Edward Snowden, and the journalists who are writing stories based on his whistleblowing, we now know that the Obama administration is collecting oceans of our data. Martin Luther King Jr was a dissident, an organizer, a critic of US wars abroad and of poverty and racism at home. He was spied on, and his work was disrupted by the federal government.

The golden anniversary of the March on Washington is 28 August. Deeply concerned about the crackdown on dissent happening under Obama, scholar Cornel West, professor at Union Theological Seminary in New York, wondered if "Brother Martin [King] would not be invited to the very march in his name."

Denis Moynihan contributed research to this column