Notice that the exception called "Glomar" refers to the non-release of information that would tend to show that a specific person or persons were under some sort of criminal investigation.From:
I am appealing this Glomar rejection. The NSA justified
its Glomar Response with generalized and abstract explanations that are
insufficient to carry the government’s burden of justifying its refusal
to confirm or deny. To call a public mailing list "SIGINT related
material" is farcical.
Please answer this appeal with continued processing of my request. Please confirm receipt of this appeal.