The basis for Gang Stalking is STASI

High level summary about STASI as it pertains to Gang Stalking

(Stasi was the official state security service of the German Democratic Republic (East Germany)

"Full-time officers were posted to all major industrial plants (the extensiveness of any surveillance largely depended on how valuable a product was to the economy) and one tenant in every apartment building was designated as a watchdog reporting to an area representative of the Volkspolizei. Spies reported every relative or friend who stayed the night at another's apartment. Tiny holes were drilled in apartment and hotel room walls through which Stasi agents filmed citizens with special video cameras. Schools, universities, and hospitals were extensively infiltrated.

Information gathered about the latter groups was frequently used to divide or discredit members. Informants were made to feel important, given material or social incentives, and were imbued with a sense of adventure, and only around 7.7%, according to official figures, were coerced into cooperating.

A large number of Stasi informants were tram conductors, janitors, doctors, nurses and teachers; Mielke believed that the best informants were those whose jobs entailed frequent contact with the public.

The Stasi employed one full-time agent for every 166 East Germans. The ratios swelled when informers were factored in: counting part-time informers, the Stasi had one informer per 6.5 people. By comparison, the Gestapo employed one secret policeman per 2,000 people. This comparison led Nazi hunter Simon Wiesenthal to call the Stasi even more oppressive than the Gestapo.

The Stasi perfected the technique of psychological harassment of perceived enemies known as Zersetzung – a term borrowed from chemistry which literally means "decomposition".

By the 1970s, the Stasi had decided that the methods of overt persecution that had been employed up to that time, such as arrest and torture, were too crude and obvious. It was realized that psychological harassment was far less likely to be recognized for what it was, so its victims, and their supporters, were less likely to be provoked into active resistance, given that they would often not be aware of the source of their problems, or even its exact nature. Zersetzung was designed to side-track and "switch off" perceived enemies so that they would lose the will to continue any "inappropriate" activities.

Tactics employed under Zersetzung generally involved the disruption of the victim's private or family life. This often included psychological attacks, such as breaking into homes and subtly manipulating the contents, in a form of gaslighting – moving furniture, altering the timing of an alarm, removing pictures from walls or replacing one variety of tea with another. Other practices included property damage, sabotage of cars, purposely incorrect medical treatment, smear campaigns including sending falsified compromising photos or documents to the victim's family, denunciation, provocation, psychological warfare, psychological subversion, wiretapping, bugging, mysterious phone calls or unnecessary deliveries, even including sending a vibrator to a target's wife. Usually, victims had no idea that the Stasi were responsible. Many thought that they were losing their minds, and mental breakdowns and suicide could result.

One great advantage of the harassment perpetrated under Zersetzung was that its subtle nature meant that it was able to be plausibly denied."