Check out Gilmore v Gonzales: http://en.wikipedia.org/wiki/Gilmore_v._Gonzales

John Gilmore sued then-attorney general Alberto Gonzales in 2005, complaining (among other things) that when airport security refused to let him on a flight without showing ID, that no one would tell him which law made that a requirement. Because that law was a Secret.

He lost. As best I can tell, he lost without him or his lawyers ever getting to see the text of the law he was theoretically violating.