In his office in the Executive Office Building, President Richard Nixon meets with Attorney General John N. Mitchell, left, and FBI Director J. Edgar Hoover, in Washington on May 26, 1971. (Henry Burroughs/AP)

On March 24, 1971, I became the first reporter to inform readers that the FBI wanted the American people to think there was an “FBI agent behind every mailbox.” That rather alarming alert came from stolen FBI files I had found in my own mailbox at The Washington Post when I arrived at work the previous morning. ¶ It was the return address on the big tan envelope that prompted me to open it first: “Liberty Publications, Media, PA.” I had worked at the Evening Bulletin in Philadelphia before coming to The Post in January 1970, so I knew of Media, a small town southwest of Philadelphia. ¶ The letter inside the envelope informed me that on the night of March 8, 1971, my anonymous correspondents — they called themselves the Citizens Commission to Investigate the FBI — had broken into the Media FBI office and stolen every file. They did so, I learned later, in the dark and as the sounds of the first Muhammad Ali-Joe Frazier boxing match filled the streets.

“Enclosed you will find,” the letter said, “copies of certain files from the Media, Pennsylvania, office of the FBI which were removed by our commission for public scrutiny. We are making these copies available to you and to several other persons in public life because we feel that you have shown concern and courage as regards issues which are, in part, documented in the enclosed materials.”

I wasn’t aware of having shown any courage, but I was, to put it mildly, eager to read those files — 14, as it turned out, of 1,000 files that they had taken.

For 43 years the people who sent those files to me then have remained unknown to the general public. This week, five of the Media FBI burglars — a group that pulled off an act that led to congressional investigations of all intelligence agencies, congressional oversight and significant reforms in the FBI — are coming forward for the first time.

Cover of The Washington Post from March 24, 1971. (The Washington Post/The Washington Post)

In a book I have written and in “1971,” a documentary film by Johanna Hamilton, the burglars tell their story — the ultimate result of a chance encounter I had at a dinner party in 1989 with acquaintances in Philadelphia, who told me they were involved in the Media burglary.

There were eight of them. Seven have now explained why and how they broke into an FBI office, with five of them revealing their names: William C. Davidon, then a physics professor at Haverford College and the leader of the group, who died in November; John C. Raines, then and until recently a religion professor at Temple University; Bonnie Raines, a day-care center director then and since the director of organizations that advocate for children; Keith Forsyth, then a cabdriver and now an electrical engineer; Bob Williamson, then a social worker and now a life and business coach based in Albuquerque. The other surviving burglars who came forward live in Philadelphia.

‘Enhance the paranoia’

When I first looked at the contents of that envelope from Liberty Publications, I had no idea who might have done such a thing.

The first file I read grasped my attention. In it, FBI agents were encouraged to increase interviews with dissenters “for plenty of reasons, chief of which are it will enhance the paranoia endemic in these circles and will further serve to get the point across there is an FBI agent behind every mailbox.”

If the FBI had paranoia as a goal of its intelligence operations, it was significant news.

Every document told a story about FBI power that was unknown to anyone outside the FBI. One, signed by FBI Director J. Edgar Hoover on Nov. 4, 1970, had two subject headings — “Black Student Groups on College Campuses” and “Racial Matters.” It was the first of numerous FBI files I would receive from the anonymous burglars over the next two months that revealed Hoover’s programs targeting African Americans. The files revealed that African American citizens were watched by FBI informers everywhere they went — the corner store, classrooms, churches, bookstores, libraries, bars, restaurants. Every FBI agent was required to hire at least one informer to report to him regularly on the activities of black people. In the District, every agent was required to hire six informers for that purpose. On one campus in the Philadelphia area, Swarthmore College, every black student was under surveillance.

In these documents, Hoover conveyed a sense of urgency about the need to monitor black students: “Initiate inquiries immediately. I cannot overemphasize the importance of expeditious, thorough, and discreet handling of these cases. . . . Increased campus disorders involving black students pose a definite threat to the Nation’s stability and security.”

When I finished reading the files I received that day in March, I knew I held in my hands either a cruel hoax or information the American public needed to know about its most powerful law enforcement agency and the FBI director it had long adored.

Within an hour, the FBI confirmed that the files were, indeed, copies of the ones stolen from the Media office.

By late afternoon, when I submitted my article, I was surprised to learn that it might not make it into the paper. Attorney General John N. Mitchell, who would later serve time in prison for his role in the Watergate affair, had called two editors, executive editor Ben Bradlee and national managing editor Ben Bagdikian, multiple times that afternoon urging them not to publish.

Two members of Congress — Sen. George S. McGovern (D-S.D.) and Rep. Parren J. Mitchell (D-Md.) — and the Washington bureaus of the New York Times and Los Angeles Times had also received the files. All four of those recipients immediately handed them over to the FBI.

Late that afternoon, Mitchell called the publisher, Katharine Graham, and again demanded that The Post not publish an article. Finally, at 6:45 p.m., he released a statement urging “anyone with copies of the records to neither circulate them further nor publish them.” Disclosure of the files we possessed, he said, could endanger lives, disclose national defense information and give aid to foreign governments.

Tough words, especially for an attorney general who, I discovered years later from the 33,698-page record of the FBI’s official investigation of the Pennsylvania burglary, had neither read nor been briefed on the files before he issued those dramatic claims.

At first, Graham did not want to publish the article. The Post’s legal counsel, Tony Essaye, also opposed publication. After hours of heated discussion on the unprecedented question of whether to publicize secret government documents stolen by people outside the government, Graham approved publication at 10 p.m. The story was immediately released on The Post’s wire service and appeared the next day on the front pages of many papers, including The Post.

The editors had convinced Graham that the responsibility to reveal this information far outweighed concern about how it became available to us. It was important for people to have access to the information — even if it were the fruit of a burglary — that the FBI engaged in practices that had never been reported, probably were unconstitutional, and were counter to the public’s understanding of Hoover and the FBI.

The reaction to the story was swift and angry. Members of Congress who had never expressed anything but kind words for J. Edgar Hoover and the FBI now issued unprecedented calls for a congressional investigation of the bureau.

Covering up COINTELPRO

One of the most important Media files was a mere routing slip. On the top of it was the then-unknown term COINTELPRO. That program included clandestine efforts that the Rev. Martin Luther King Jr. and his closest associates interpreted at the time as a blackmail threat intended to persuade King to commit suicide. Hoover desperately wanted to keep the operation secret.

Because I wrote about the document attached to the routing slip, Hoover and his top aides knew on April 6, when that article was published, that the term COINTELPRO was known outside the department. Hoover immediately wrote to the heads of all field offices conducting these top-secret counterintelligence operations and ordered them to stop submitting status letters, apparently in an effort to increase security. At the same time, he told them they must “continue aggressive and imaginative participation in the program.”

Three weeks later, fear that the operations would one day become public convinced Hoover to take the more extreme step of eliminating the code name COINTELPRO. Officials were to say the program had been closed. Actually, it continued, but with no name.

The nature of the program was first revealed in 1973 by NBC journalist Carl Stern, who successfully sued the FBI for documents that defined the purpose of COINTELPRO, which was initiated by Hoover in 1956. Numerous such operations were revealed during the 1975 hearings of the Senate select panel known as the Church Committee, the first congressional investigation of all intelligence agencies.

A surprise at dinner

Many years after the Media burglars opened the door to Hoover’s secret FBI, I accidentally found two of them, John and Bonnie Raines. On a trip to Philadelphia in 1989, I had dinner at their home one evening. I had known them as acquaintances when I worked in Philadelphia in the late 1960s and had not seen them for many years. Their youngest child joined us briefly. John turned to her and said, “Mary, we want you to know Betty because many years ago, when your dad and mother had information about the FBI we wanted the American public to know, we gave it to Betty.”

That statement didn’t mean anything to Mary, but it almost knocked me off my chair. When she left the room, I asked the obvious question: “Are you saying you were the Media burglars?”

They happily admitted they were. John Raines had not planned to tell me, he says. He just happened to blurt it out. Among the many things I learned that night was that the eight burglars had all agreed to take the secret to their graves. A few weeks later, I asked them if they would find the others and together consider breaking that vow so that this important gap in history could be filled. Shortly after that, on a part-time basis while I continued to teach journalism, I started my research about them, the investigation into the burglary and the impact of what they had done.

As the Media burglars came forward this week, inevitably people have linked them to former NSA contractor Edward Snowden, who last year began releasing documents showing massive government surveillance.

There are similarities in their stated motivations: They all sought to give important information to the public about overreaching intelligence agencies.

Davidon, the leader of the Media group, thought that suppression of dissent was a crime against democracy. If documentary evidence was presented to Americans, he was confident they would take action to stop it. He was right. The burglars found the evidence and the public acted.

In the case of the Snowden files, it is not clear what action the public might demand that Congress take.

It is clear, though, that twice in the past half-century, Americans have had to rely on burglars — not official oversight by Congress, the Justice Department or the White House — for crucial information about their intelligence agencies’ operations.

Betty Medsger, a former Washington Post reporter, is the author of “The Burglary: the Discovery of J. Edgar Hoover’s Secret FBI.”