Our personal space is dear to us all. We live our lives in full public view on social media – posting photos of the food we just ate or even expressing intimate feelings for our loved ones – but there are still things we would rather not share with the world. Indeed, it is privacy that sets man apart from the animals who must stick together in the wild for their own safety. But mankind was not born private. Our primitive ancestors too lived in large groups, every member of which knew all there was to know about the others. Privacy evolved over time as man developed technologies to wall himself off, even as he remained part of the society at large.