In the past, when I’ve introduced systems theory concepts and their applicability to public relations, I’ve had trouble persuading students of the possible existence of closed systems organisations. Surely all organisations are – or at least aspire to be – open?
So now I turn the question on its head. Surely all organisations are based on some variant of the ‘command and control’ structure of the army. Surely all organisations strive to be as closed as they can be (hence their procedures and attempts at news and information management).
But isn’t it getting harder to remain closed in our interconnected age of 24/7 news? Don’t most countries have border controls? And don’t many governments apply some form of censorship and impose media controls? Aren’t blogs banned in some countries (and in some companies too)?
Don’t be too quick to dismiss the existence of closed systems organisations – though as Scoble and Israel point out in Naked Conversations, you might choose not to work for one of them.
PR Studies 
Every organization has some necessary secrets. But it turns out they succeed with far fewer of them than they realize. The more open they are, the more helpful and supportive their customers become. As for the Army you mentioned, the military was the first to realize that the more decisions made at the from line rather than at HQ, the better the army performs in the field.