German researchers used ordinary WiFi signals instead of cameras to identify people; the result turned everyday wireless networks into a powerful new way to recognize individuals with nearly 100% accuracy

WiFi signals can now do more than connect devices. Researchers showed that ordinary wireless networks can detect and identify people without cameras, special sensors, or a phone. In a study of 197 people, the system achieved nearly 100% identification accuracy. It read changes in radio waves as they moved around human bodies. The finding raises a new privacy concern. Everyday WiFi could quietly become a powerful surveillance and human recognition tool.