For Israel, losing control of its data to authorities overseas was a significant concern. So to deal with the threat, officials created a secret warning system: the companies must send signals hidden in payments to the Israeli government, tipping it off when it has disclosed Israeli data to foreign courts or investigators.

Named after the towering cloud formations, the Nimbus contract – which runs for an initial seven years with the possibility of extension – is a flagship Israeli government initiative to store information from across the public sector and military in commercially owned datacentres.

Even though its data would be stored in Google and Amazon’s newly built Israel-based datacentres, Israeli officials feared developments in US and European laws could create more direct routes for law enforcement agencies to obtain it via direct requests or court-issued subpoenas.

With this threat in mind, Israeli officials inserted into the Nimbus deal a requirement for the companies to a send coded message – a “wink” – to its government, revealing the identity of the country they had been compelled to hand over Israeli data to, but were gagged from saying so.