Ever been stuck behind a login portal after connecting to supposedly "open" Wi-Fi? This can happen on airplanes, in hotels or airports, or even at coffee shops that force you to agree to a term of service. In order to get around these distractions, we can simply scan the area for devices that are already connected, and change our MAC address to look like theirs.
This allows us to join the network without seeing the login portal. It's an awesome way to add an IoT device to an open network with a portal, as your device would otherwise get stuck behind the portal.