invisible fiber optic cabling is an installation that hides fiber optic wiring inside a building or structure, often used to improve aesthetics and protect the fiber from external damage. It is commonly found in homes, offices and commercial environments. Researchers at NDSS 2026 demonstrate a covert acoustic eavesdropping attack that transforms standard FTTH telecom fiber cables into passive, undetectable listening devices invisible to RF scanners and immune to ultrasonic jammers. Security researchers from The Hong Kong Polytechnic University, The. Fiber optic cables, widely trusted for delivering fast and secure internet, have now been shown to pose an unexpected privacy risk. A device that can pick up tiny changes in signals sent through the cables can detect.