In 1955 the banker and amateur mycologist R. Gordon Wasson persuaded a Mazatec healer, Maria Sabina, to admit him to a velada in Huautla de Jimenez. In 1957 he published an account of it in a mass circulation American magazine. He changed her name; it was identified within months.
What followed is the clearest case in this atlas of the harm publication can do. Huautla received a continuous stream of outsiders who wanted mushrooms and had no interest in the ceremony, the language or the illness the ceremony was for. The Mexican authorities eventually intervened. Sabina's house was burned, her son was killed, she was ostracised by neighbours who held her responsible for what had arrived, and she died in poverty. She said in later years that from the moment the foreigners came, the mushrooms lost their power, and that they had been profaned.
The scholarly value of the record is real and so is the cost of obtaining it, and the two do not cancel out. This is the standing case cited in debates about consent in ethnobotany and about what it means to publish a living practice.
The mushrooms are now the centre of a well funded clinical research programme in psychiatry, conducted almost entirely without reference to the tradition that preserved them. Whether that constitutes a debt, and to whom, is an open question the field has not answered.