In 2010, four years after Facebook launched in Europe, Rob Leslie had a hunch. He felt privacy “was going to be a thing”. “When I started looking at this, nobody gave a shit about privacy; it was give me your data, give me as much as you can and I’ll promise you the world, and it’ll all be fine and dandy,” he recalls. “I’m old enough to know that’s the story until it all goes pear-shaped and something goes catastrophically wrong, as it will, and we’re starting to see that now.” At the time, Leslie came across a new cryptographic…