Whenever we visit come place, the first thing we search for is good network connectivity. And Wi-Fi always provides fast and secure connectivity. The task of downloading and also the loading of the internet pages becomes much simpler and faster with the presence of Wi-Fi.
But there are certain soft wares which kills the Wi-Fi connectivity and terminates the internet connection on any device which is connected to the Wi-Fi network. With the help of Wi-Fi killers, you can also block anyone from using your Wi-Fi. This also maintains the security of your connection. This reduces the amount of stealing network and will also let you know if someone is using your Wi-Fi connection.
It also helps you in checking those who are connected to the same Wi-Fi and using it. 2 of the most commonly used Wi-Fi killers are WifiKill and Netcut. They first scan all the users who are using the same Wi-Fi and note down their MAC address. Once the list is ready, you can choose whom you want to keep and whom you want to stop from using the connection.
It is mainly used in the android app and Netcut is used in Windows. Faceniff is also Wi-Fi killer but is rarely used when compared to both wifikill and netcut.
Legally, you can block people from outside if they are trying to secretly use your Wi-Fi connection and make it secure and private. The practice becomes illegal when you are at a public place and you try to block the Wi-Fi connection which is actually for everyone to use.