Here When you get a mac they block Ip:port proxy settings and set it to proxy.greendale.k12.wi.us so your interwebz go though them
Easy to bypass though
My School has a VPN that u can use to access Facebook before and after school hours

and u can use ur own VPNS during school if u juss change the network location to "Home" and network to "Guest" lol idiot tech people :p