It was a tactic eerily reminiscent of Hitler's Third Reich: German youths used by the secret police to spy on their elders for a totalitarian regime.
It happened in communist East Germany on a scale few imagined, according to a Lutheran clergyman who was targeted by youthful informers."Perhaps we had a rough idea that something was going on. But none of us knew the dimensions," the Rev. Rudi-Karl Pahnke said. "We did not know that a 13-year-old could be cooperating."
Pahnke co-authored a new book, "Damaged Souls," that examines how youths recruited by the East German secret police suffered psychological damage in betraying friends and mentors.
The book, published in German, reports a surprising number of young spies: An estimated 17,000 youths ages 14 to 25 were among the 174,000 "unofficial collaborators" of the Ministry for State Security, known as the Stasi.
Many turned to alcohol and drugs after East Germany collapsed in 1989-90. Others have been unable to maintain personal relationships or have become withdrawn out of guilt, the book says.
Stasi chief Erich Mielke first proposed recruiting spies under 25 in the early 1960s to curb youthful "nonconformity" in the rigid communist system. Eventually youths under 18 were used to report on schoolmates and to infiltrate the punk rock, heavy metal and skinhead scenes.
The informers also reported on their teachers and on church groups that adults couldn't easily infiltrate, the book says.
When Pahnke looked into his own Stasi files in 1991, he was stunned to discover that half of the 18 informants spying on him were teenagers he had counseled at his East Berlin church.
The Stasi files were opened to the general public in 1992. Since then, 1.2 million Germans have applied to examine their files, and about 800,000 have done so.
Ulrike Poppe, a former dissident, said the book is a reminder of the cruelty of the East German communist system.
"I see a strong trend now, the growing idea among people from (East Germany) who want to believe that it was a friendly country, bound by solidarity, and simply don't want to see how cold and brutal the methods of the dictatorship really were," she said.
Cornelia Bull, a spokeswoman for the federal commission for Stasi archives, said the spying was similar to that done by the Nazis, who encouraged children to spy on their families.
But she said the comparison can be taken only so far - unlike in the Nazi era, where being caught by the Gestapo usually meant a concentration camp or worse, those who didn't toe the line in East Germany were more likely to lose a job or promotion or be denied permission for a trip.
"Damaged Souls" deals mainly with the psychological effects on the young spies. The authors interviewed ex-spies and examined Stasi files. Full names of those interviewed aren't disclosed because they were minors when they col-lab-o-rat-ed.
Most often, Stasi agents targeted youths who got into trouble with the authorities, offering them a way out if they cooperated. Many of the youths are still scarred.
Rudolph was expelled from school at 17 for political activities he wanted to conceal from his mother. To keep his secret and resume his studies, he reported on friends and colleagues from 1981-85.
"The burden of a schizophrenic, double existence brought me to the edge of what I could bear," Rudolph writes.