Posts Tagged ‘Berlin’

Stasi / Facebook / Big Data DAAD Day 28 – The Stasi Archive and BStU

Sunday, June 25th, 2017

After some traveling and conferences and development sprints on other projects I have time this week to come back to the Stasi work. The first post is about the Stasi Records Agency (BStU), whose full name (in English) is the impressive, “Federal Commissioner for the Records of the State Security Service of the former German Democratic Republic”.


Monday Demonstration in Leipzig on 16 October 1989

At the end of 1989 the Peaceful Revolution spread across the former East Germany. These protests led to the opening of the border via the emotional breaking apart of the Berlin Wall, as well as the end of the reign of the SED government, and with it, the Stasi.

During the transition protesters realized the Stasi agencies were destroying the files that could incriminate them. Groups of citizens occupied Stasi offices across East Germany and sealed the buildings to prevent further destruction of information. On January 15, 1990, citizens gained access and occupied the Berlin headquarters of the Stasi.

After German reunification the BStU was established to preserve the archives and investigate the past of the Stasi. Since January 1992 they have provided a service to allow citizens to view the Stasi files that concern them.

In Berlin the BStU is located at 31 Karl-Liebknecht-Straße, with the files appropriately continuing to be located in the former Stasi headquarters on Frankfurter Allee in Lichtenberg. Here are some photos I took inside the archives in the former Stasi headquarters.


An example card from the Stasi card index now used to locate information for citizens wanting to know what data the Stasi collected, Stasi Records Agency, 2017


Shelves of citizen files now open to view by the citizens the Stasi surveilled, Stasi Records Agency, 2017


Microfiche shredded by Stasi agents, Stasi Records Agency, 2017


Shelves of surveillance video, Stasi Records Agency, 2017

In addition to providing access to citizen’s files, the BStU assists scholars by allowing viewing of other Stasi documents. In my case, their staff helped me to find and view schematics of postal surveillance machines prepared by the Stasi OTS.


Detail of the Stasi Automatic Letter Closing Machine schematic, Stasi Records Agency, 2017

The BStU also has a thorough library at the Karl-Liebknecht-Straße location. Unlike the Stasi documents, which require one to make an application as a scholar, the library is open to the public.


The BStU library, 2017


A Deutsche Welle report on the Stasi archives, 2010

Stasi / Facebook / Big Data DAAD Day 11 – Kerblochkarten

Tuesday, May 16th, 2017


A Stasi Kerbloch card

The Stasi used several other card systems to assist their postal surveillance. The Kerblochkarten (English: Kerbloch cards) system allowed storage of data encoded as a series of hand-made notches. Like other punch card systems, groups of cards could then be automatically processed by a machine based on the presence of notches and a predefined key. The Kerbloch card system made it possible to perform statistical evaluations and targeted searches on up to 350 cards/persons at a time. Importantly, this card amended the functionality of the the F16 cards and allowed the Stasi to quickly search for potential informants by querying characteristics relevant to a particular job. While anyone who has used a computer spreadsheet software today would take this sorting and searching functionality for granted, this was a highly useful tool for the Stasi, which by 1989 had amassed over 39 million index cards. (The Key to Power, 5)

  1. The key to power: Card indexes and other finding aids practices of State Security. Archivar 64. Jahrgang Heft 04 November 2011.
  2. BStU: Kerblochkarten (KK)

Stasi / Facebook / Big Data DAAD Day 10 – Card systems of the Stasi

Monday, May 15th, 2017

The early days of the Stasi were marked by the development of new systems for monitoring the population. In the 1950s, having already incorporated a post-WWII file system used for denazification, the MfS implemented three new index card types to track citizens, all of which were stored in a central card index. These cards were distinguished by color and used to track persons considered hostile to the state (form A1 which was yellow), official staff (form B1, later replaced by the blue and grey F19), and persons who were arrested (the red, form C1).

While official staff had titles and were on the payroll, the Stasi used hundreds of “unofficial staff.” These “Inoffizielle Mitarbeiter” (or IMs) were either foreign citizens who turned over valuable information like trade secrets, or domestic informants who spied on their colleagues, neighbors, and relatives (and sometimes even spouses). While money was a primary motivation, they were compelled for a number of other reasons, including blackmail, ideological commitments to the GDR, or gifts other than money, like lavish vacations, prostitutes, and official state awards. In fact, the Stasi implemented an impressive number of medals and rewards in order to convince both IMs and official staff to maintain loyalty and faithfully contribute their labor to the state. (Macrakis, loc 386) These awards are not unlike the loyalty cards, badges, and other gamification tactics that today’s corporations employ across their databases of customers in order to increase brand allegiance and sales.

Similar to modern software development, the Stasi index card systems, like many of their methods over the years, were constantly being reworked and improved with each new iteration. For example, while the previous system used separate cards to track “enemies” and “friends,” as the Stasi learned to coerce those formerly consider hostile into becoming secret informants it became necessary to track persons who evolved into “frenemies of the state.”

This situation presented a particular problem, as the Stasi needed to record and track personal data on these people, but their real identities needed to be protected should they agree to turn over valuable information. For these persons the Stasi implemented a separate “transaction card” (F22) that augmented the standard cards. The change updated the yellow card (F16, formerly A1), which contained the real name, address, birth date and place, occupational status, workplace or school, and the red card (F18, formerly C1), used for those arrested, which contained this information, as well as a mugshot, a visual description, and data related to their crime, and added a registration number if they were a Stasi informer or agent. (The Key to Power, 3–4)


The central operation card “F22” Credit: BStU

The new “transaction card” (F22) recorded Stasi informants only by this registration number, as well as a secret code name and name of the case officer who managed the agent. Finding the real name of a Stasi operative meant matching not only the registration numbers on these cards, but additional comparisons, because many agents purposely shared registration numbers to add extra layers of secrecy. (Macrakis, 78) This method is similar in theory to modern relational database lookup tables, where a user’s personally identifiable information (PII) is separated and protected from data dumps containing so-called “anonymized data” , or public key encryption, where data is transmitted securely by performing mathematical operations on it using a combination of a unique private and public key.

  1. The key to power: Card indexes and other finding aids practices of State Security. Archivar 64. Jahrgang Heft 04 November 2011.
  2. Macrakis, Kristie. Seduced by Secrets: Inside the Stasi’s Spy-Tech World (Kindle Location 1615). Cambridge University Press.
  3. Jason Koebler This Visualization of NYC’s Taxis Shows the Promise and Pitfalls of Big Data Motherboard (2014)
  4. Alex Hern New York taxi details can be extracted from anonymised data, researchers say The Guardian (2014)

Stasi / Facebook / Big Data DAAD Day 9 – MfS Department M (1960’s developments)

Thursday, May 11th, 2017

The implementation of zip codes across West Germany in 1961 made it much easier to monitor postal traffic between east and west. The Berlin Wall was erected in that same year, leading to a heightening of Cold War suspicions and increased emphasis on monitoring movement of information between east and west.

The 1960’s also saw the various reorganizations and new leaders, including Lieutenant-Colonel Walter Mehrbach, whose years of experience in the postal service led to the development of the first training manual for Department M, and certification courses in mail surveillance at the MfS Law School in Potsdam. (Labrenz-Weiß, 21)

As Department M grew in the 1960’s, so too did the amount of mail they examined and information they recorded. This demand for intelligence required constantly expanding data storage methods, which led the department to develop a card system for efficient alphabetical sorting and identification of people, places, and objects on both sides of the East/West German border. (Labrenz-Weiß, 19) I’ll dig in a little deeper over the next few days on these cards, for now a photo from my BStU archive research last summer:


BStU: MfS, BV, Potsdam, Abt II 764 pg 6

  1. Hanna Labrenz-Weiß, Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.

Stasi / Facebook / Big Data DAAD Day 8 – MfS Department M (A captured letter from the BStU archives)

Tuesday, May 9th, 2017

The Stasi Mediathek website published by the BStU is an amazing resource. One can search for example “Abteilung M” (English: Department M) and find a range of digitized original documents related to the Stasi’s postal surveillance.

This is an example of a letter that the Stasi Department M removed from the Deutsche Post in 1962. In the letter an East German student writes to her friend in the west about her dissatisfaction with the militarism and compulsory conscription in the east and says she is considering fleeing the GDR. Surely the Stasi placed her under a watchful eye due to the information they found through their postal surveillance. It’s also interesting the Stasi one, removed the letter altogether from the postal stream, likely in order to prevent negative sentiments from appearing in western press, and two, kept the document, perhaps as evidence against her at a later date, or potentially also as a result of the thoroughness of the bureaucratic surveillance system they had developed. An English translation can be found at the above link as well. (BStU)

Stasi / Facebook / Big Data DAAD Day 7 – MfS Department M (Development of working methods)

Tuesday, May 9th, 2017

In the early years of the Department M, or Division VI as it was known at the time, there was no vocational training so the few dozen employees had to conceive of their own workflows. At that time, the standard set for workers who examined the contents of mail was to read “500 letters per person for each working hour.” Post control took place in special rooms of selected central post offices, where employees of Division VI covertly intercepted and opened mail. The onsite locations helped to ensure the Stasi could accumulate as much intelligence as possible while causing the lowest acceptable delay in the Paketstrom (English: packet stream). (Labrenz-Weiß, 13)

By 1952 Department M was established and locations for inspection were formalized. The five GDR states (see previous blog post) were divided into 14 districts in order to increase efficiency by moving postal control structurally closer to sender and receiver. Various statutes were established by the MfS allowing for inspection of the post in order to prevent sedition inspired by western influence, as well as to carry out censorship through interception of materials. The process for post control was also more precisely defined and subdivided into specific working groups for: 1) Sorting mail by size; 2) Technical processing; 3) Readers; 4) Writers; and 5) Employees at the lamp.

Units responsible for “Sorting” the mail passed any letters or parcels that appeared suspicious, as well as all mail destined for persons or organizations under postal control, to “Technical processing” where it was opened using steam or other nondestructive methods. It was then sent to “Readers” who sent letters to the “Writers” once it was determined the contents were worthy of being transcribed. The Writers had the job of recording the documents, preparing reports for each day, and passing information with clues for espionage, sabotage, or, after the addition of the Berlin wall, plans for escape, to relevant departments.

“The work on the lamp” investigated suspicious consignments in a dark room under a quartz lamp in order to identify clandestine forms of communication like secret writing on the surface of paper, or other methods including invisible ink. If found these documents were then passed to the OTS, or Operational-Technical Sector of the MfS, for special investigation.
These early divisions of labor served to increase efficiency much in the same way Henry Ford had done at the beginning of the century when he introduced the assembly line. Equally, the divisions helped Stasi employees to become more knowledgeable and specialized in their work, eventually developing machines to augment, improve, and speed up their tasks. (Labrenz-Weiß, 16–17)

  1. Hanna Labrenz-Weiß, Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.

Stasi / Facebook / Big Data DAAD Day 6 – MfS Department M (postal control selection)

Monday, May 8th, 2017

Stasi Department M workers removed enormous amounts of mail from Deutsche Post each day for inspection. Mail was identified visually based on handwriting, types of letters, or specific addresses. Surveillance of mail was technically illegal in the GDR. Still, mail was withheld on an official basis “in order to prevent attacks” by western intelligence agencies, presumably using “threats and explosives.” This led to the inspection of all incoming and outgoing mail to press agencies, embassies and consulates of NATO countries, and other western correspondence.

Unofficially, in the interest of multiple surveillance, control and censorship possibilities for the Stasi, everything possible was scrutinized, both foreign and domestic. The postal inspections contributed intelligence on GDR and foreign citizens who were suspected of spying for the west. They allowed the Stasi to filter information the citizens of the GDR were allowed to access, share, or communicate to the outside world. The Stasi intercepted undesirable books, seditious content, and other materials with the ultimate goal of preventing public protests, or other conspiratorial activities. While the goal of Department M was to return the mail collected for inspection back to Deutsche Post within a 12-hour window, many deliveries were seized and never returned. This massive operation naturally resulted in frequent delays in delivery or damage to letters or parcels, which including those that never arrived, led the public to become increasingly aware of the ongoing postal inspection.

Finally, the postal surveillance provided the Stasi with information about the mood of the population in the GDR, by examining personal communications, as well as messages sent between in companies and institutions. Reports prepared by administrators in Department M on population mood included information on economic and political sentiment and specifically targeted demographic groups (Labrenz-Weiß, 13) across specific geographic locations and social strata in the GDR in order to give the best possible assessment. For example, the following population groups are described in BStU documents

  • Brandenburg: 1,000 workers each at the East coaster and the Brandenburg Steel Works, and 1,000 old and new builders
  • Mecklenburg: 1,000 workers of the shipyards, 500 students and 50 teachers of the University of Rostock, and 1,000 old and new builders
  • Saxony-Anhalt: 1,000 workers of the chemical industry and of Magdeburg heavy machinery construction, 800 students and 100 faculty members of the Martin Luther University Hall, and 1,000 old and new farmers in Altmark
  • Saxony: 1,000 workers of the Stahlwerk Riesa as well as tradesmen / merchants, and 800 students and 100 lecturers from the University of Leipzig
  • Thuringia: 1,000 workers of the Unterwellenborn steelworks, Zeiss works in Jena and tradesmen, and 800 students and 100 professors of the Jena University


East Germany’s State borders established after WWII 1945-1947 in violet. In red the borders of the new states established during reunification. Source: Wikipedia

  1. Hanna Labrenz-Weiß, Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.

Stasi / Facebook / Big Data DAAD Day 5 – MfS Department M (Organizational structure overview)

Thursday, May 4th, 2017

In 1989 Department M had 10 divisions, which were subdivided into 36 units. The head office, which consisted of 8 divisions and their corresponding units, was located in East Berlin. The divisions were organized based on mail destinations (western, non-communist countries for example), types of mail (like parcels or telegrams), or function within the scope of the work of the Department. Specific units were tasked with selecting mail for examination, while in technical processing units the selected mail was opened, examined, documented, and closed again by their respective units. Other units in Department M were assigned to inspecting customs declarations, maintaining secrecy, or operational engineering, where design, manufacturing, and maintenance of the technology took place. (Labrenz-Weiß, 8–10)

  1. Hanna Labrenz-Weiß, Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.

Stasi / Facebook / Big Data DAAD Day 4 – MfS Department M (the workers)

Thursday, May 4th, 2017

The Stasi surveilled the post of the GDR for nearly 40 years, starting with the founding in 1950, until the fall of 1989 when the Berlin wall fell. The number of workers in Department M rose from a few dozen in the beginning, to nearly 2,200 by the end. The largest office occupied two buildings in the massive Stasi headquarters complex in Berlin-Lichtenburg and included almost 500 employees, with the remaining 1,700 spread across 15 district administration offices. (Polzin, 105)

While the ratio of women to men in Department M shrank over the years possibly due to the increasing focus on technology and automation, it was consistently at least twice that of the entire MfS. In the beginning 80% of Department M employees were women, compared with 25% in the MfS, while in the 1960s 40% were women compared to 14%. In 1989 only 20% of Department M employees were women. (Labrenz-Weiß, 5)

Employees were subject to numerous specialized training to prepare them for their work. This included courses on typography, x-ray certification, and photography for those performing inspections. Employees who were integrated with Deutsche Post received information like electronic training for working with telegraph devices, operating postal vehicles, and other knowledge related to the movement of mail and parcels. Those employees charged with the development of specialized equipment for Department M studied engineering, paper technology, air and refrigeration systems, and the mechanics around the movement of postal and newspaper materials. (Labrenz-Weiß, 6)

While Department M employees were physically embedded in Deutsche Post locations, their activities there were considerably constrained in order to ensure the secrecy of their work. For example, they were required to sit in closed groups in the cafeterias in order to avoid direct contact with actual postal workers. Official contacts were only allowed with Stasi officers already embedded in the post control system special operations.

  1. Arno Polzin, Postal Inspection, Telephone Surveillance and Signal Intelligence in Daniela Münkel (eds.), State Security: A Reader on the GDR Secret Police, Berlin 2016.
  2. Hanna Labrenz-Weiß, Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.

Stasi / Facebook / Big Data DAAD Day 3 – MfS Department M

Wednesday, May 3rd, 2017

The Ministry for State Security’s Department M was tasked with “postal control”, or the inspection of domestic and international letters and packages. They conducted their work thanks to cooperation with Deutsche Post which, as another state institution concerned with “security of the state,” was subject to the same politics and power infrastructure of the single party system of the DDR (1). Consequently, the Department M had access to every letter and parcel which traveled throughout East Germany by inserting itself in the logistical operations of the postal system. The Stasi reserved special rooms or entire floors within the Deutsche Post buildings, which were off limits to regular post workers.

In Berlin, Department M had offices in the post office at Nordbahnhof, in the central telegraph office on Oranienburger Strasse and in the railway post office at Ostbahnhof. These rooms used by the MfS were designated “Department 12” of the German Postal Service, both internally and officially.(2)

  1. Arno Polzin, Postal Inspection, Telephone Surveillance and Signal Intelligence in Daniela Münkel (eds.), State Security: A Reader on the GDR Secret Police, Berlin 2016.
  2. Hanna Labrenz-Weiß: Abteilung M (MfS Handbuch). Hg. BStU. Berlin 2005.