DNA analysis is a powerful tool for researchers, scientists and law enforcement. But in the everyday lives of people across the globe, affordable access to DNA testing has brought about a seismic shift. For the first time, donor conceived people can find their biological fathers, mothers or siblings. Donor conception has exploded in the last three and a half decades, but around the world it faces little regulation. Fertility clinics public and private have operated without limits on the numbers of children created from individual donors, without health checks, and largely with impunity.