I don't see why this is a big deal. It's the school's computers and they should be able to regulate them any way they choose. It's no different from the workplace where an employer dictates what can and cannot be done on his computers.
FWIW, back in junior high, we were forbidden to use even the payphones without a note from a parents. I thought that was a bit tough and never understood that rule. In HS they didn't care except when we snuck a call on a school telephone.
Except > Gee. Shouldn't they also ban all other forms of communication? I'd
Sorry, but that's not how it works today. Like it or not, the schools (as does businesses) have a very legitimate concern. If their facilities are used utilized adversely, they could be held liable. As such, they must protect themselves.
There was a newspaper article reporting that schools are a lot quicker to suspend kids (a serious punishment) than in years past. It's not that kids behave worse, but rather schools are afraid of a lawsuit from an aggrieved parent if they fail to aggressively punish a wrong-doer. Also, some schools are merely returning to discipline standards they held in the past, but relaxed in more recent years.
In some ways, I think schools acting to prevent harassment/ bullying between students is not such a bad idea.