We've tended to avoid an approach that overemphasizes blocking parts of the Internet. We have the software to do it, and we have limited certain things, especially for certain kids. But, for the most part, we've manages our netbooks by walking around and monitoring what kids are doing. Our parents, too, have gotten involved. The more tech-savvy parents, or the ones with kids who are tech-savvy, have installed software on their kids' netbooks that allow them (the parents) to be notified when the kids are straying from acceptable usage while on the Internet.
We tend to deal with the abuse and the abuser while avoiding a blanket approach that assumes kids cannot be trusted with the technology tools we want them to use. So far, it's been working out. Have we had any glitches? Yes. We've dealt with these situations on a case by case basis, and that seems to be working fairly well so far.
What we've learned from a few years with this system is that we need to do a better job of parent orientation and education, and enlist our parents in monitoring their own child's usage. I encourage my students and parents to create a pact. I encourage them to have all computer time in a public area within the home. Rather than spending the evening in their bedrooms unsupervised, my students are encouraged to do their computer-based work in full view of their parents. I then tell the parents that I've given their children this advice, and I ask them to do their part by being available while their child is working on the netbook at home. This fosters trust, communication, and good practices for a child whose primary purpose in having his own netbook at school and at home is to use it as a learning tool. At school and at home I encourage game-playing and other toy oriented usage of the netbook as a reward for diligently using the netbook as a learning tool throughout the day and week. I use Class Dojo (see my article on Carrots and Sticks) to keep track of the positive use of netbooks and the rewards are clearly earned by the student.