United States | News & Politics

Digital security (like the Snowden leak) is completely separate from physical document security.

For physical security, it seems plausible to just put a tag on every official document, whether mundane or classified, which would complicate tracking efforts by a potential enemy since they'd have to sift out the noise. If documents aren't out of storage very long, the tags can be cycled with other documents to further confuse an attacker. That's a bit "security through obscurity," but AFAIK that's kind of the game you okay with physical documents.

Also, I think the FBI/CIA would be more interested in knowing which of the documents went missing in the event of a leak than having a slight bit more obscurity to prevent long-ish range tracking. If they have a mole that can help them know which documents are interesting, they can just steal the documents anyway.

Then again, maybe this is why I'm not in OpSec for classified documents.