Some specific case:
1 If a foreign young people will marry a developed country's citizen or permanent resident. After they will have married. But the foreign spouse will refuse to go to work most of the time, to rely her (or his) spouse (citizen or permanent resident of the country) to supply her (or him). Whether the citizen or permanent resident have enough money and stable work. This situation can be accounted as fake marriage (If the foreign spouse will still refuse to go to work since the near future).
2 If a child will over 18 years of age, their parents have the right to expel the adult child out of their home.