Sadaf was at work last year at the attorney general¡¯s office in suburban Kabul when her sister rang with news that the Taliban had entered the Afghan capital, and begged her to race home.

¡°Cover your face! And don¡¯t tell anyone where you work,¡± her sister said, her voice shaking with fear.

Sadaf didn¡¯t know it then but this was the start of exile within her own country, a life of lying low to avoid death by data. Like thousands of Afghans, she has spent the past year hiding out in a series of safe houses, hoping to evade her digital trail and prevent the Taliban tracking her family.