In 2014, Steve Bannon – then executive chairman of the “alt-right” news network Breitbart – was Wylie’s boss. And Robert Mercer, the secretive US hedge-fund billionaire and Republican donor, was Cambridge Analytica’s investor. And the idea they bought into was to bring big data and social media to an established military methodology – “information operations” – then turn it on the US electorate.

It was Wylie who came up with that idea and oversaw its realisation. And it was Wylie who, last spring, became my source. In May 2017, I wrote an article headlined “The great British Brexit robbery”, which set out a skein of threads that linked Brexit to Trump to Russia. Wylie was one of a handful of individuals who provided the evidence behind it. I found him, via another Cambridge Analytica ex-employee, lying low in Canada: guilty, brooding, indignant, confused. “I haven’t talked about this to anyone,” he said at the time. And then he couldn’t stop talking…

Wylie oversaw what may have been the first critical breach. Aged 24, while studying for a PhD in fashion trend forecasting, he came up with a plan to harvest the Facebook profiles of millions of people in the US, and to use their private and personal information to create sophisticated psychological and political profiles. And then target them with political ads designed to work on their particular psychological makeup.

“We ‘broke’ Facebook,” he says.