Four Decades Before Edward Snowden, Activist Burglars Exposed FBI’s Cointelpro Program has produced an excellent short video, embedded above, telling the story of the March 8, 1971 burglary of FBI offices in Media, Pennsylvania that exposed the agency’s Cointelpro program. The identity of the activists was unknown until this week, when some of them stepped forward ahead of the release of a book about the burglaries.

Just as Edward Snowden’s 2013 leak of classified information about NSA surveillance contributed to the public debate about overreach by government spies, the Media burglars exposed an illegal surveillance program. Cointelpro, short for Counter Intelligence Program, was created to spy on civil rights leaders and other activists, but it went further. Among the revelations from the burglary was evidence that the FBI attempted to anonymously blackmail Martin Luther King, Jr. into committing suicide.

Then as now, the government attacked the whistleblowers, saying that they should have used legal methods to expose injustice. The problem with that argument is that in both the case of Cointelpro and the case of NSA mass surveillance, until activists took action, the public did not know it was happening.