I work for a school system and we have an all or nothing policy when it comes to the network, Why? People bring in their own wireless routers, they don't change the default password, and leave dhcp on. Eventually, people get 192.168.x.x addresses, instead of 10.x.x.x, this cuts them out from internet access. Then we get 15 tickets in the same building over 1 router. It gets better, then I have to find it, easy enough with my phone or tablet with a wifi finder app, but then I have to explain to the user why they can't have it. All of you here know how that goes so I'll spare you. After all that, then I have to physically go to all 15 users and reset their connections, because our helpdesk is useless and dameware never seems to work. Wasted productivity? You betcha.
I have recently come up with a way to better convince people to leave their shit at home. I break into their unsecured router, with no wireless password, and set one. or if they have files shared I access those and copy them to a USB stick, and then delete the original files. After showing the user all the things I was able to do in about 2 minutes, they usually don't complain.
This one lady though was a real pain, I told her, politely, why we can't allow these things about 5 times, she would take it back home for a week or so and cause the mess in the 1st paragraph after about 2 or so weeks again. I went to my boss, the principal, you name it and this woman refused to stop it. One day, after the 50th ticket caused by her, I had had enough. I got into the router and flashed the wrong firmware to it, bricking it. She hasn't done it since.