cultural appropriation
noun /ˌkʌltʃərəl əˌprəʊpriˈeɪʃn/
  /ˌkʌltʃərəl əˌprəʊpriˈeɪʃn/
[uncountable] (disapproving)- the act of copying or using the customs and traditions of a particular group or culture, by somebody from a more dominant (= powerful) group in society 
- The novelist has been accused of cultural appropriation for basing the story on a Navajo legend.