Here’s one school system’s take on using their web filter:
What we’ve decided is that we will no longer use the web filter as a classroom management tool. Blocking one distraction doesn’t solve the problem of students off task – it just encourages them to find another site to distract them. Students off task is not a technology problem – it’s a behavior problem. It is our intention that we help students to learn the appropriate on-task behaviors instead of assuming that we can use filters to manage student use.