Wi-Fi The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. Some are abusing this technology that is why a paint that could block outsiders to use your internet was invented.

Mixing aluminum-iron oxide particles with paint results the metal particles resonate just like the frequency as Wi-Fi and other radio waves, that is why signals will not be able to pass through the thin layer of pigment. University of Tokyo developed this invention. The paint is said to be the first that can block radio frequency in higher spectra where Wi-Fi and other higher-bandwidth communications occur rather than just low-frequency wireless like FM radio. Most Wi-Fi technologies operate at 2.4GHz; the Tokyo paint can reportedly block frequencies all the way up to 100GHz, with a 200GHz-blocking paint now in the works. Outsiders would be unable to access your wireless network and vice versa. If your inside your house you won’t be able to interlope on anything beamed on the outside.

The paint isn’t just of interest to those concerned about wireless leaking out of the building. Movie theaters have long been interested in finding a legal way to keep cell phones silent during screenings. Electronic jammers that actively block wireless signals are illegal, but passive materials that prevent wireless signals from getting through are not. Since the wireless-blocking paint can also block the lower-frequency signals that cell phones use, addled mobile junkies would have no outlet for reaching the outside world.