Illegal emigration refers to a person moving across national borders in a way that violates emigration laws. Such a person may legally go abroad and refuse to return when demanded by the country of origin.
Russia implemented emigration restrictions two months after the Russian Revolution of 1917, with the various Soviet Socialist Republics of the Soviet Union thereafter banning emigration. After the creation of the Eastern Bloc from countries occupied by the Soviet Union during World War II, Eastern Bloc countries instituted emigration bans similar to those in the Soviet Union. After the erection of the Berlin Wall in 1961, emigration except for ethnic migration reasons mostly halted from east-to-west, though a few thousand escape attempts from East Germany occurred, including those by defecting border guards. (More generally, escape by any citizen was considered defection.) North Korea also strictly controls emigration.
Special cases are when one flees a country as a refugee escaping persecution, or after committing a crime, trying to escape prosecution. However, as an illegal immigrant one may be sent back, and as a criminal, one may face extradition or prosecution in the other country.
The stance of the United Nations is that freedom to emigrate is a human right, part of the right to freedom of movement. According to the Universal Declaration of Human Rights, "Everyone has the right to leave any country, including his own, and to return to his country".
Eastern Bloc 
Emigration and any travel abroad were not allowed without an explicit permission from the government and KGB. People who were not allowed to leave the country are known as "refuseniks". During the final stages of World War II, the Soviet Union began the creation of the Eastern Bloc by directly annexing several countries as Soviet Socialist Republics that were originally effectively ceded to it by Nazi Germany in the Molotov-Ribbentrop Pact. These included Eastern Poland (incorporated into two different SSRs), Latvia (became Latvia SSR), Estonia (became Estonian SSR), Lithuania (became Lithuania SSR), part of eastern Finland (became Karelo-Finnish SSR) and northern Romania (became the Moldavian SSR). Other states were converted into Soviet Satellite states, such as the People's Republic of Poland, the People's Republic of Hungary, the Czechoslovak Socialist Republic, the People's Republic of Romania, the People's Republic of Albania, and later East Germany from the Soviet zone of German occupation.
By the early 1950s, the Soviet approach to controlling national movement was emulated by most of the rest of the Eastern Bloc (along with China, Mongolia and North Korea). Up until 1952, the lines between East Germany and the western occupied zones could be easily crossed in most places. Accordingly, before 1961, most of that east-west flow took place between East and West Germany, with over 3.5 million East Germans emigrating to West Germany before the 1961, On August 13, 1961, barbed-wire barrier that would become the Berlin Wall separating East and West Berlin was erected by East Germany. Two days later, police and army engineers began to construct a more permanent concrete wall.
In East Germany, the term Republikflucht (fugitives from the Republic) was used for anyone wishing to leave to non-socialist countries. A propaganda booklet published by the Socialist Unity Party of Germany (SED) in 1955 for the use of party agitators outlined the seriousness of 'flight from the republic', stating "leaving the GDR is an act of political and moral backwardness and depravity", and "workers throughout Germany will demand punishment for those who today leave the German Democratic Republic, the strong bastion of the fight for peace, to serve the deadly enemy of the German people, the imperialists and militarists".
Famous defectors include Joseph Stalin's daughter Svetlana Alliluyeva, Mig-25 pilot Viktor Belenko, U.N. Undersecretary General Arkady Shevchenko, chess grand master Viktor Korchnoi, ballet stars Mikhail Baryshnikov, Natalia Makarova and Alexander Godunov. Famous East German defectors include author Wolfgang Leonhard, East German soldier Conrad Schumann who was photographed jumping the Berlin wall while under construction and a number of European football players, including Jörg Berger. While media sources often reported high level defections, non-prominent defections usually went unreported.
The Cuban government currently forbids its citizens from leaving or returning to Cuba without first obtaining permission from the government. In a translation by Human Rights Watch, under Cuba’s criminal code, individuals who, “without completing legal formalities, leave or take actions in preparation for leaving the national territory” can face prison sentences of one to three years in prison. From 1985 to 1994 the number of illegal emigrants is estimated to 82,500, with an additional 7,500 up to the mid-2000.
Even discussing illegal emigration carries a six-month prison sentence.
UPDATE: Law-Decree 302, published in the Official Gazette of the Republic of Cuba on October 16, shall enter into force on 14 January 2013. The Immigration law of the Cuban regime eliminates the need for an exit permit but increases passport costs to 100 CUC, the equivalent of 5 months of average salary.
It is illegal for an Iranian woman to leave Iran alone without written permission from her husband or male relative if she is not married. Any woman of any nationality married to an Iranian man automatically becomes an Iranian citizen and is subject to these regulations. Betty Mahmoody, married to Iranian Sayyed Bozorg Mahmoody, was trapped in Iran after her husband had decided that they would stay there during a two-week vacation. She had to escape to Turkey aided by smugglers because she would not have legally been allowed to leave Iran without first obtaining a divorce from her husband, who would have gained full custody of their daughter, Mahtob. Betty tells her story in her Pulitzer-nominated book Not Without My Daughter.
Until 1974 individual freedom to emigrate from Portugal was subordinated the aims of the state. The 1933 Constitution says that "The state has the right and the obligation to coordinate and regulate the economic and social life of the Nation with the objective of populating the national territories, protecting emigrants, and disciplining emigration." The state tried to attain three key goals with this policy: meet labor needs, satisfy interests in Africa, and ensure benefits from emigrant remittances. At least 36 percent of Portuguese emigrants between 1950 and 1988 left the country illegally.
According to Human Rights Watch, the government of Burma has tightly restricted the number of Muslims allowed to travel to Mecca for the Haj pilgrimage. Muslims claimed they continue to have difficulties getting passports to travel abroad.
Child support: Australia, New Zealand, United States 
If a person owes more than $2,500 in child support, he or she cannot get his or her US Passport renewed and therefore will not be able to leave the United States and could be deported back to the United States for not having a valid US passport. Australia and New Zealand have a travel ban for people who owe child support.
- The Sound of Music — 1965 movie fictionalizing the von-Trapp family fleeing the Nazis in Austria of 1938 and secretly escaping over the Alps to freedom in Switzerland (Italy in real life)
- Balseros — Documentary about escaping Cuba on rafts
See also 
- Korea: North, Amnesty
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- Roberts 2006, p. 43
- Wettig 2008, p. 21
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