Defenders of the integrity of indigenous religion use the term "plastic shaman" to criticize those they believe are potentially dangerous and who may harm the reputations of the cultures and communities they claim to represent. There is evidence that, in the most extreme cases, fraudulent and sometimes criminal acts have been committed by a number of these imposters. It is also claimed by traditional peoples that in some cases these plastic shamans may be using corrupt, negative and sometimes harmful aspects of authentic practices. In many cases this has led to the actual traditional spiritual elders declaring the plastic shaman and their work to be "dark" or "evil" from the perspective of traditional standards of acceptable conduct.