The bracelet is like an anti-smartwatch, both in its cyberpunk aesthetic and in its purpose of defeating technology. A large, somewhat ungainly white cuff with spiky transducers, the bracelet has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound is imperceptible to most ears, with the possible exception of young people and dogs, but nearby microphones will detect the high-frequency sound instead of other noises.
Woodrow Hartzog, a law and computer science professor at Northeastern University, doesn’t think privacy armor is the solution to our modern woes.
Rather than building individual defenses, Mr. Hartzog believes, we need policymakers to pass laws that more effectively guard our privacy and give us control over our data.