People have access to only 3% of existing fruits and vegetables. The other 97% - two million « Farmers’ seeds » varieties - are illegal, because a producer can only grow and sell what is registered in the Official Catalogue of Authorized Species, defined by the agrochemical lobby. This is the law in Europe and mostly all over the world. As a result, 90% of farmable varieties have already disappeared worldwide since the 20th century (FAO), farmers depend on hybrids, and consumers are deprived from a wide range of superior produces, richer in nutrients, taste, and better for the environment. Carrefour, the French retailer and leader in Europe, has long fought for a more sustainable agriculture and healthier food, and decided to use its leadership power to change the law. To change the law, Carrefour defied the law by creating The Black Supermarket: a place to sell illegal varieties of cereals, vegetables, and fruits in its stores nationally. The campaign challenged people to go to the Black Supermarket and encouraged them to sign our petition on change.org to change the law. Against powerful lobbies, we chose the illegal path to make sure we’d be heard by key opinion leaders, the public, and politicians up to Brussels where decisions are made. The campaign changed people’s opinion onCarrefour « the big retailer ». Even the worst critics of the retail industry joined our cause. As a result of our efforts, a new law proposal was voted in November 2017, and was ratified by the European parliament on April19th 2018, reauthorizing sale and cultivation of farmers’ seeds.