Can someone explain to me why the fuck do I have to fake mac address on 3 of my devices only so I can use the internet I paid for on my collage?

We can have connected on 1 caple only 1 device. Seems reasonable. So why the fuck do they keep on checking, if I ever dare to disconnect that cable and use another device?

I am asking a moral question. What is the reason they would even feel like they need this information?