I love how people always say what the schools need to do, but offer no viable suggestions regarding how to implement them in the school system.
Should we offer a Facebook class? Ok, what would this look like? You can't just let kids run wild on these sites, as no learning would occur. So what if we create assignments that have to be completed using collaboration among students using Facebook? Sounds good, but try putting a room full of teenagers on the internet and then keeping them on task. It's difficult at best and impossible at worst.
Even if they do stay on Facebook, what happens when little Sarah meets her 'dream guy' online, who turns out to be a psycho stalker adult? Who gets the blame? The school/teacher. And when a group of students uses a school computer to gang up on a kid using cyber-bullying? Again, the school/teacher gets the blame.
Give me a practical way to implement this type of thing and then I'll listen. Believe me, my ears are open. I want to do it.