School bans dictionary

I follow a lot of library and edtech listservs and nearly every week someone, somewhere is attempting to ban a book. As much as I hate censorship, sometimes they are legitimate, such as a book that is truly YA and somehow found its way into an elementary collection. The latest to hit the newswires is a book banning in California involving the dictionary. Apparently there are collegiate level dictionaries in the upper elementary classrooms for advanced students and spelling bee practice. Naturally, some curious students "stumbled" across certain terms as children will do and the parents were not thrilled. Makes one wonder: 1) how far will "protecting" our children go and 2) do we want them finding out correct definitions from the playground, Wikipedia or edited & factual referene sources like the dictionary?