(CNN) -- The sometimes ludicrous disguises and complex surveillance techniques used by East Germany's Stasi secret police to psychologically brutalize the population have been revealed, more than two decades after the fall of the Iron Curtain.
From 1950 onwards, the Stasi infiltrated almost every aspect of society and by the mid-1980s, a vast network of unofficial informants and full-time employees had been created. Some spouses spied on their partners, as did neighbors and friends. The ratio of 80,000 full-time agents to the 16 million people in the GDR was higher even than in Soviet Russia.
After the fall of the Berlin Wall in 1989 and Germany's reunification the following year, most of the Stasi archives were opened to the public. Citizens can request their Stasi files from the BStU, revealing the meticulous surveillance they had been subjected to during the Cold War era.
Now the extent to which East Germans were being watched is documented in a new book by Simon Menner.
"People are fascinated by surveillance and secret services, but the public has little access to picture material showing the act of surveillance," the Berlin-based artist told CNN.
In his book "Top Secret: Images from the Stasi Archives," Menner includes images that show the creative guises of Stasi personnel. "Most people would probably laugh seeing these pictures now. They look almost ridiculous," he said, "but they show a dark chapter of German history."
For more than two years, Menner, 35, went through thousands of images and documents at the archive of the Federal Commissioner for the Stasi Archives of the former German Democratic Republic (BStU). "These images offer a glimpse into another world, an extinct culture, but it was a brutal system that showed no sympathy for its people," he said.
"The fact that Stasi spies had to try to look like ordinary people just shows that they had completely lost the connection to their citizens."
The aliases of people that spied on them are also in the files and on request the real names can be uncovered. Last month Peer Steinbrück, who is running against Angela Merkel in the race to be Germany's next chancellor released his Stasi file online, revealing that on his visits to the GDR a relative reportedly spied on him.
According to Menner, thousands of bags of Stasi images and documents are yet to be archived. "I have just scratched the surface and many secrets remain unknown."