The first sign that our cyberweapons were boomeranging back was the commotion outside London’s hospitals on May 12, 2017. Ambulances were getting diverted. Emergency rooms were turning people away. Patients were being rolled out of the operating room on gurneys, told their surgeries would have to be postponed to another day. Nearly fifty British hospitals had come under assault from the most vicious ransomware attack to hit the internet.
