When East Germans finally gained access to the records of their secret police, some discovered that the person who had informed on them for years was a coworker, a pastor, a close friend, or a spouse. The files were measured not in pages but in kilometers of shelving. They are the most complete record we have of what happens when a state sets out to know everything about its people, and they explain why many Europeans, and Germans above all, take privacy so seriously.

The Stasi

The Ministry for State Security of the German Democratic Republic, known as the Stasi, was founded in 1950. It described itself as the "shield and sword" of the ruling party. By 1989 it had about 91,000 full time employees and roughly 189,000 unofficial informants in a country of about 16 million people. Counting former informants, a far larger share of the population had worked with it at some point.

The Stasi opened mail, tapped phones, bugged apartments and even kept jars of cloth holding the scent of suspects so that dogs could track them. Its most powerful tool was people. Unofficial informants were recruited among friends, neighbors, coworkers and family members, often through pressure or small favors. Because anyone might be reporting, people learned to guard their words even at home.

By the 1970s the Stasi relied less on open arrests, which damaged East Germany's image abroad, and more on a method it called Zersetzung, meaning "decomposition." Officers quietly wrecked the lives of targets: spreading rumors, arranging failures at work, sowing distrust in marriages, moving objects in apartments so that targets doubted their own minds. The goal was to break people without leaving visible fingerprints.

Opening the files

As the regime collapsed in late 1989, citizens noticed smoke rising from Stasi offices: officers were destroying records. Crowds occupied the office in Erfurt in early December 1989, and protesters entered the Berlin headquarters in January 1990. After reunification, Germany passed a law in 1991 under which, from January 1992, East Germans won the right to read their own files. Millions of requests followed. Teams have since worked to piece together bags of torn pages that officers did not have time to destroy.

The decision to open the files was controversial. Some feared it would tear families and communities apart. Supporters argued that people had a right to know the truth about their own lives, and that hidden files would leave the old power intact. Most Germans today regard the choice as right, painful though it was.

Democracies too: COINTELPRO

It would be comforting to think that only dictatorships abuse surveillance. The history of the United States says otherwise. From 1956 to 1971 the FBI ran a set of programs called COINTELPRO, short for Counterintelligence Program. It began by targeting the Communist Party and expanded to civil rights groups, antiwar activists, Black nationalist groups, and also the Ku Klux Klan. The aim went beyond gathering evidence of crimes: agents tried to discredit, divide and disrupt lawful political movements.

The most notorious case involved Martin Luther King Jr. The FBI wiretapped him and bugged his hotel rooms, and in 1964 the FBI sent King an anonymous letter urging him toward suicide, along with a recording meant to threaten his marriage.

COINTELPRO came to light because of a 1971 break-in at an FBI office in Media, Pennsylvania. A small group of activists stole files and mailed them to newspapers. The resulting stories led to congressional investigations, most famously the Senate's Church Committee of 1975 and 1976, named for Senator Frank Church. Its reports documented decades of spying on Americans by the FBI, the CIA and the National Security Agency.

Reforms followed. The Foreign Intelligence Surveillance Act of 1978 created a special court that must approve electronic surveillance for foreign intelligence purposes inside the country, and Congress created permanent intelligence oversight committees.

Lessons, fairly stated

The agencies involved believed they faced real threats. Soviet espionage in the United States was genuine, and some groups the FBI watched did plan violence. That context matters. Yet the record shows a pattern that recurs across very different countries: surveillance created for one set of threats tends to spread to lawful critics and dissenters. Secrecy prevents the correction that would otherwise check it. Both East Germany and the United States show that the safeguard is not good intentions but outside oversight.

Worked example: reading your own file

Vera Lengsfeld was a peace and environmental activist in East Germany, arrested in 1988 and pushed out of the country. After reunification she read her Stasi file and learned that her husband, Knud Wollenberger, had been reporting on her to the Stasi for years under a code name.

Her case shows each idea in this level. The informant was the closest person in her life, which is why the system worked: no one could feel fully safe anywhere. The harm went beyond the arrest to the wound in her family. Her right to read the file did not undo that harm, but it gave her the truth about her own life and ended the state's monopoly over the story. Her case is also why privacy laws in Germany emphasize a person's right to know what is recorded about them, the same right that later appears in European data protection law.