http://news.bbc.co.uk/2/hi/asia-pacific/4720386.stm
"Selayang is an area where the capital's migrant workers live, legally and illegally. For years Malaysia has been trying to contain a burgeoning number of illegal migrant workers.
In late 2004 it declared an amnesty allowing hundreds of thousands of illegal immigrants - mostly from Indonesia and the Philippines - to leave before launching a major operation to deport the rest in March last year. But illegal immigrants still make up a large population - hundreds of thousands of people, according to estimates - and the economy depends heavily on foreign workers. "
