Marx describes that in ancient societies the production of surplus labour takes the form of forced overwork or forced labour until death. He discusses the capitalist contradiction between necessary and surplus labour-time that results in class struggles. Marx speaks in the context of the "surplus population" that migrates from agricultural regions to the cities where the flight from rural areas and urbanisation processes connected to it are not limited to the 19th century but continues to shape the global capitalism. The exploitation of slave-workers in Nazi Germany is an infinite form of exploitation which is the realisation of the dream of all capitalists to not have to pay workers anything. Poverty is a factor that favours child labour and makes children vulnerable to exploitation and the labour regulation can try to reduce the child labour. The International Labour Organization (ILO) prohibits the worst forms of child labour namely: slavery, prostitution, drug trafficking, and hazardous labour.