A hacker repurposed a cheap Wi‑Fi smart bulb into a covert “dead‑drop” for censored literature, calling the project Banned Book Library. By flashing the device with open‑source Tasmota firmware, the bulb runs its own access point and web server, letting anyone nearby download stored PDFs when the light is on. The approach exploits the bulb’s unobtrusive form factor to evade detection.

The hardware centers on an ESP32‑C3 chip with 4 MB flash, sold with Tasmota. The limited storage forced the builder to consider a microSD add‑on, but extracting the ESP32 required prying apart aluminum housings and removing potting compound—a messy, risky process that could compromise safety. A small soldering iron and hand suffice, but the aluminum shielding demands careful cutting to avoid damaging the antenna or circuitry.

After soldering wires to the exposed GPIO pins for serial programming, the author flashed a custom image that hosts a tiny HTML index of book files. While the prototype proves the concept, the need for invasive disassembly and limited flash space make widespread deployment impractical without redesign. The experiment highlights how consumer IoT can be turned into low‑profile information caches.