The issue here is not the rightness or wrongness of this case but the secrecy of it that remains unconfessed by the secreters.
You might find this interesting.
The first link spells out what "Sensitive" or, what is being called secret information, is.
This is statutory i.e. mandated and codified by Congress.
As written it's easy to see why they might want to keep certain information and activities from being disclosed.
They also wrote the measure in a way that does afford the public a certain measures of protection of their privacy.
In the current topic/court case, it appears that in the absence of a different ruling from higher up's, the FAA personal are prohibited by law from even disclosing certain information to the judge in the case?
The Congress has made its case for the "rightness" to keep certain information secret by law.
Is it wrong?
§ 15.5 Sensitive security information.
http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?region=DIV1;type=boolean;c=ecfr;cc=ecfr;sid=10abd9cafe510979b789edd3bb8f086f;q1=passenger;rgn1=Section;op2=and;q2=screening;rgn2=Section;op3=and;rgn3=Section;view=text;idno=20040518;node=20040518%3A1.0.1.3;rgn=div7
PART 1520—PROTECTION OF SENSITIVE SECURITY INFORMATION
http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?region=DIV1;type=boolean;c=ecfr;cc=ecfr;sid=10abd9cafe510979b789edd3bb8f086f;q1=passenger;rgn1=Section;op2=and;q2=screening;rgn2=Section;op3=and;rgn3=Section;view=text;idno=20040518;node=20040518%3A1.0.2;rgn=div5