Silicon Valley owes its existence to the US government — in particular, the defence department. It was long the tech industry’s most important customer, as well as the funder of foundational research.

The relationship does not look so good these days. Microsoft chief executive Satya Nadell a this week became the latest tech executive to distance his company from contracts it has with the US government. Its work with Immigration and Customs Enforcement has not sat well with some employees, given the agency’s recent involvement in separating families entering the US illegally.

Earlier this year a Microsoft executive bragged in a blog post that the company’s technology had received official certification from ICE, enabling the agency’s staff to do things such as use its facial recognition software to identify people. But this week Mr Nadella insisted the relationship was limited to “supporting legacy mail, calendar, messaging and document management workloads”. The clear implication: Microsoft would think twice before helping ICE implement any controversial Trump immigration policies.