Dunno about listening devices, but certainly tracking devices: Remember this from a few years back - http://www.zeit.de/datenschutz/malte-spitz-vorratsdaten htt

Dunno about listening devices, but certainly tracking devices: Remember this from a few years back - http://www.zeit.de/datenschutz/malte-spitz-vorratsdaten http://www.zeit.de/datenschutz/malte-spitz-vorratsdaten - a guy retrieved all information his telco had on him under some kind of freedom of information laws, and he threw it all up online. Someone then took the data, mashed it up with his public tweets/posts and made this cool interactive map/visualisation showing exactly what he'd been up to.