A Wi‑Fi jammer is a gadget designed to knock wireless devices off a hotspot. Why would anyone need that? Think of it as a prank (your neighbor will be thrilled when you cut off his porn video or, say, a soccer match at the most exciting moment), but it also has criminal uses: an attacker could take surveillance cameras or other critical equipment offline. In this article, we’ll cover low-cost hardware deauthers (deauthentication devices), how to use them, and how to protect against such attacks.