Recently i have signed up to the new Google+ social network and well its basicly facebook BUT their is one aspect of it that beats facebook and tramples on its corps, it cant be blocked without completly blocking google so to block google+ in a school would mean students would not be able to acces the google search bar and would most probably disrupte most internet based assignments.
It is very straight forward to use and the games on there are pretty much the exact same as facebook's collection so its handy when in a class room