One reason why though, is that the Gestapo could rely on ordinary Germans to inform on each other. It didn't need a vast network of agents and microphones, it just needed an office to take complaints and detectives to follow up.

Unlike the Nazis, who were homegrown, the DDR was a locally administered occupation government backed by a foreign power. It was terrified of its own people and it collapsed the moment the threat of Red Army tanks rolling down the streets quit being credible.

Indeed it was, the resistance movement tried bombed the office keeping the census data in Amsterdam in 1943 since it was so effective for the Nazis. It kept the data of over 70.000 Jews in the Amsterdam. The resistance was active in forging identity cards and having the population registry destroyed meant that there would be nothing to compare the identity cards to. Unfortunately, the bombing only resulted in the destruction of 15% of the data. Many of the resistance fighters involved were executed shortly after.

The Stasi weren't involved with that, as they did not exist until 1950.