A number of splinter groups have separated from Jehovah's Witnesses since 1931 after members broke affiliation with the Watch Tower Bible and Tract Society of Pennsylvania. Earlier group defections from the Watch Tower Society, most of them between 1917 and 1931, had resulted in a number of religious movements forming under the umbrella term of the Bible Student movement. After 1931, some isolated groups of Jehovah's Witnesses came to distrust instruction from outside the local area. Some preferred their autonomy even after persecution and isolation abated, such as in Germany following World War II, in Romania following the overthrow of Nicolae Ceaușescu, and in the former USSR following the Cold War. Beginning in the 1990s, other former Witnesses used Internet technologies to group themselves around shared ideas such as numerical analysis of the Bible, or a wish to embrace some but not all of Jehovah's Witness beliefs and practices. Britain Jesse Hemery was appointed overseer of the Watch Tower Society's British Isles branch office by Charles Taze Russell in 1901, holding that post until 1946. Hemery founded the Goshen Fellowship after he was disfellowshipped by Nathan H. Knorr in 1951. Germany, postwar Scholars estimate that during the Nazi regime, about half of all Jehovah's Witnesses in Germany were incarcerated in prison or concentration camps, where they were exposed to "sadism marked by an unending chain of physical and mental tortures, the likes of which no language in the world can express." At the time, they were represented by several geographical Bible Students Associations, each of which considered itself affiliated with the Watch Tower Society despite little contact with their US headquarters in Brooklyn. When contact was re-established, a minority of German Jehovah's Witnesses either preferred their autonomy or disagreed with the doctrinal changes that had occurred in the meantime. Some disassociated themselves from the Watch Tower Society and some individual members established contact with non-Jehovah's Witness Bible Student groups. Romania In 1948, the Romanian government imposed a ban on Jehovah's Witnesses that lasted until 1989. Many Witnesses were arrested and sent to prison or labor camps, and members of the denomination had limited communication with other Witnesses and studied largely from older books and magazines. In 1962, The Watchtower altered its doctrine on the meaning of the phrase "superior authorities" at Romans 13:1, identifying them as human governmental authorities rather than God and Jesus Christ as formerly thought. Many Witnesses