Hacker packs 537,000 ad‑blocking domains into $5 ESP32 dongle

A hacker engineered a tiny ESP32‑based dongle for ad‑blocking. The device costs roughly five dollars. Its firmware stores a list of 537,000 domain names. The domain list fits within the limited memory of the chip. The firmware occupies about 50 KB of RAM. Lookup queries for blocked sites are answered in about 10 ms. This demonstrates high‑density filtering on inexpensive hardware. The approach could inspire low‑cost network‑wide ad‑blocking solutions.