Larry makes an interesting point about our students now being able to go where they wish on their own devices while they are in school.
Not so long ago we could wrap the kids in bubble wrap while they were in school (over filter) and not worry what they were doing when they left the building because it wasn't our responsibility. That has changed.
Even CIPA now requires that we TEACH digital citizenship. The focus is shifting from protecting the school from liability to educating the kids on how to use the Internet responsibly.
Is over filtering enabling staff to pretend that the Internet in school is safe and we don't need to deal with appropriate use issues?
Would opening up Facebook force people to deal with when it is appropriate and when it isn't?