 Border controls thereafter strengthened such that, by 1928, even illegal departure was effectively impossible.This later included internal passport controls, which when combined with individual city Propiska ("place of residence") permits, and internal freedom of movement restrictions often called the 101st kilometre, greatly restricted mobility within even small areas of the Soviet Union.After the creation of the Eastern Bloc, emigration out of the newly occupied countries, except under limited circumstances, was effectively halted in the early 1950s, with the Soviet approach to controlling national movement emulated by most of the rest of the Eastern Bloc.