Why so many SBU's? It's a combination of reasons.
- The official classification system is limited and rigid--only three markings so they have been amplified by modifications.
- Bureaucrats are scared--suppose this paper leaks to the Post, that would be embarassing. Or even if it reaches the local gossip. (The Plame affair revealed that even deputy Secretaries of State can love their gossip.)
- There's the high school clique reaction: we know something you don't, ha ha ha.
- Most of all, bureaucrats love to set boundaries and SBU's are a way of marking them.
The problem we have in homeland security is that our bureaucracies have each had their own objective(s). When the global war on terrorism came along, we superimposed new objectives on the old and we still haven't straightened things out yet.