Scientists in Germany have demonstrated a startling new form of surveillance: identifying people using nothing more than ordinary WiFi signals. By analyzing how radio waves bounce around a room, researchers can effectively “see” and recognize individuals — even if they are not carrying a device and even if their phone is turned off.
That’s connection history. CSI motion detection software storing information it collects would be entirely independent of that. How much it saves and for how long would depend on the size of the router’s memory.