That's exactly right. It's in the nature of ignorance that you don't know what you're ignorant of. The problem for the committee is to consider what it can do to ensure that the national interest, as opposed to the government's interest, is not compromised by making public what really shouldn't be made public. That's a difficult question in some circumstances. But you don't have the information to know what you ought to be concerned about.
On November 4th, 2009. See this statement in context.