Kali Linux is a security-focused operating system you can run off a CD or USB drive, anywhere. With its security toolkit you can crack Wi-Fi passwords, create fake networks, and test other vulnerabilities. Here's how to use it to give your own a network a security checkup.
Omg yes! They almost HAD to have wi-fi. Just imagine the muggleborns already feeling like outsiders, and coming to this new school, leaving all their friends behind, all the things they had in the muggle world, just to learn magic. Dumbledore probably gave them wi-fi so they wouldn't feel totally isolated from the world they grew up in for the last 10 years.