According to me, Facebook is a good social network: you sign up to share photos, videos, write articles or to keep in touch with your friends. Besides the most of them use it, and it is also practical.
Facebook can be a good to keep teacher-pupil and pupil-pupil interaction outside of the class. It can also help teachers to be connected with parents and to give them some important information (assignments, upcoming events...), or to show what their children do in class (with a diary for example).
The teacher must create a Facebook profile for professional use only to separate his professional and private life; plus he has to show to pupils how Facebook works.
Not to mention that the social networks used in teaching can make a course more vivid and more interesting than a traditional one.
But Facebook might become intrusive quite quickly: when you have an account, everybody (or almost) can put information or photos of you without asking for your permission, and you cannot do anything to prevent it. Plus, Facebook is completely open, you have no real privacy even if you do not post things. Moreover, you cannot completely delete your account : it is still open to everyone and everyone can put some photos of you...
So, I am not against using Facebook to teach but as a teacher, we must be vigilant and pay attention to what is being asked to do for children.
