Rodney Barnette grew up in a segregated United States. He was drafted to go to Vietnam at the age of 21 and returned a year later, wounded in the line of duty.

After his return he joined the Black Panther Party, a civil rights movement that demanded an end to police brutality and equal rights to housing and employment. But Barnette was unaware that the FBI spied on him for years.

"Despite the fact that my dad had served in Vietnam and he is taking care of his family and is just a regular citizen, this information is being collected because he's considered an enemy by his own government," says his artist daughter Sadie.

There is a long history of government surveillance of black civil rights groups in the US.

It was supposed to have ended in the 1970s, but today there is a similar threat to Black Lives Matter (BLM), a movement fighting to end systemic violence against black people.

What started spontaneously in late 2014 as a protest around the shooting of unarmed Michael Brown, bled into cities across the country where other black men and women were being killed by police. A simple hashtag became a rallying cry: #blacklivesmatter.

As the movement grew, some organisers began to feel under watch, so they filed freedom of information requests with the New York Police Department to obtain surveillance records related to BLM. But the NYPD refused.

"The greater goal ... is to cover up the extent of their political use of their police powers to oppose Black Lives Matter. Because when they undertake surveillance of Black Lives Matter, this is not law enforcement activity. Black Lives Matter is not breaking laws," says Dave Thompson, who represents some of the organisers against the NYPD.

Alex Vitale, a professor at Brooklyn College who has researched political policing for years, explains that "the history of political policing is a history of the surveillance of individuals and organisations based on their political beliefs, not on their criminal behaviour."

For organisers of BLM, the threat of surveillance is a reminder of what happened to their parents' generation. And it's just recently that people like Rodney Barnette have been able to see the extent of that monitoring.

Fault Lines reporter Femi Oke went to Oakland, California, to better understand the history of surveillance and to see how far the government can go when its powers remain unchecked.

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