We have deemed that certain content on YouTube is inappropriate for middle school students. YouTube is no longer accessible on iPads while students are outside our building's WiFi network (6-8th Grade).
We feel that there is more supervision and observation in the schools to keep it available while in the schools. Where at home, adult supervision can be limited.
We are looking to integrate an educational version of YouTube at some point called YouTube for Schools. This version will need to be setup and tested before deployed.