This is a simple case of a nanny type program or firewall block that prevents key words or sites from being viewed. They probably use a default settings program - which is meant to block kids from accessing things of "questionable" nature. such as porn / violence / etc.
Many company's with free wifi / etc - generally instal these types of blocks after complaints from "parents" who seen their little retarded kids viewing "questionable" content. I put the parents in parenthesis because they are not parents, just people who spawned kids and don't raise them to behave/act right/etc. These types of people generally send their kids to school and dont care what the teacher is telling them (unless its against some crazy belief of theirs). I should know, ive been asked to instal such stuff before - to restrict web access to various types of sites.. I hate to do it, but its the job I am paid for.
On my personal network at home, I have blocked Facebook - just because I do not agree with how they use / abuse the data they are given and get a hold of via 3rd parties. I also use various tools to keep sites from knowing much about me. Stuff that prevent scripts running in website / adverts / etc. What I do know about computer tracking of people bothers me enough, that what I dont know they can do really makes the tin foil hat come out. I installed this one add-on for my browser that allows me to see the links between various sites and how they share data as I visit them. very creepy.
