Most people think of a Wi-Fi router as just a box that brings the internet to their whole house. But there's more to these signals than just streaming Netflix or scrolling through Instagram. New research shows that WiFi can also spot and track people without needing them to carry a phone or any gadgets at all. This news has people worrying, and honestly, privacy experts are right to be nervous. What is BFId Technology? A team at the Karlsruhe In…