WE ALL rely on cobalt every time we rely on the lithium-ion batteries that power our phones, laptops and electric vehicles (EVs). But we do not always allow ourselves to remember that the world’s greatest source of cobalt by far – in terms of number of productive mines and known reserves – is the Democratic Republic of the Congo (DRC).

This means, tragically, that the material is sometimes the product of child or forced labour. Nobody knows how much – the issue is debated – but nobody denies the problem.

Does that horrific truth mean Big Tech is liable for the torture and death of enslaved cobalt miners? This week, in Doe v Apple, the US Court of Appeals for the District of Columbia said no.