I am very grateful that The Harker School does not believe in the wholesale blocking of content on the Web. Many of our compatriots in the public schools, and also in some private schools, have to deal with this issue daily, however.
KQED published this excellent article last fall about some of the myths involved in blocking websites in schools, and the author does a great job of dispelling these myths: ORIGINAL ARTICLE
This came to my attention when my friend Joe Wood shared a more recent article about what to do if your school bans useful websites.
Again, we don't really run into this problem here, but it's good to know what others are up against and perhaps even how to help your friends who work in other schools.