Perhaps one can explain how you get SSI but not have at least a Secret clearance. . .?
I hope to learn a lot of things about Secure Flight and airline passenger profiling in general, but I probably won't be able to write about it. In order to be a member of this working group, I was required to apply for a U.S. government SECRET security clearance and sign an NDA, promising that I would not disclose something called "Sensitive Security Information."
SSI is one of three new categories of secret information, all of I think have no reason to exist. There is already a classification scheme -- CONFIDENTIAL, SECRET, TOP SECRET, etc. -- and information should either fit into that scheme or be public. A new scheme is just confusing. The NDA we were supposed to sign was very general, and included such provisions as allowing the government to conduct warrantless searches of our residences. (Two federal unions have threatened to sue the government over several provisions in that NDA, which applies to many DHS employees. And just recently, the DHS backed down.)
After push-back by myself and several others, we were given a much less onerous NDA to sign.
From http://www.schneier.com/blog/archives/2005/01/secure_flight_p.html