Middlepath: I have to disagree. Yes, the parents are ultimately responsible for their children’s chinuch – but once the kids are enrolled in a school, the parents and the school need to work as a team. Saying this is my domain and that is their domain ties both parties’ hands. Parents should definitely not be completely reliant on the school to raise their kids, but a school does a lot, lot more than just teach stuff, and it’s dangerous to try to downplay the role they really do have.
Look at it this way – let’s say the parents really don’t want their kid on Facebook or whatever. If the school they choose doesn’t have rules to that effect, there will be those there who do have it, and the kids in question will probably get into it too. Of course, the opposite works as well – if the school doesn’t allow it and the parents do, you also end up at odds. The point is that there’s no way to have a defined set of standards if the two major forces in a child’s chinuch are cutting each other short. And defined standards are essential.
Agav – if you think about it, there are schools much more mainstream than Bais Rivka that have no ban on Facebook. That makes me suspect that the move may have been necessary for some reason or another. I still don’t know or want to know what the situation is, but I think there’s a lot of room to be dan l’kaf zchus.