A federal appeals court on Tuesday refused to hold five major technology companies liable over their alleged support for the use of child labor in cobalt mining operations in the Democratic Republic of the Congo. In a 3-0 decision, the U.S. Court of Appeals for the District of Columbia ruled in favor of Google parent Alphabet, Apple, Dell Technologies, Microsoft and Tesla, rejecting an appeal by former child miners and their representatives. The plaintiffs accused the five companies of joining suppliers in a forced labor" venture by purchasing cobalt, which is used to make lithium-ion batteries. Nearly two-thirds of the world's cobalt comes from the DRC. According to the complaint, the companies "deliberately obscured" their dependence on child labor, including many children pressured into work by hunger and extreme poverty, to ensure their growing need for the metal would be met. The 16 plaintiffs included representatives of five children who were killed in cobalt mining operations. Circuit Judge Neomi Rao said the plaintiffs had legal standing to seek damages, but did not show the five companies had anything more than a buyer-seller relationship with suppliers. Terry Collingsworth, a lawyer for the plaintiffs ... said his clients may appeal further. The decision provides "a strong incentive to avoid any transparency with their suppliers, even as they promise the public they have 'zero tolerance' policies against child labor," he said. "We are far from finished seeking accountability."