It's ironic that the US government, whose leaders often complain about judicial advocacy, plans to use a judicially created "State Secrets" privilege to try and have the Electronic Frontier Foundation's warrantless eavesdropping lawsuit thrown out of court. The privilege was first recognized (i.e., "made up") by the Supreme Court in 1958. The story behind that case is interesting, and provides a lesson for today's citizens.
According to first amendment lawyer Glenn Greenwald, the 1958 case was brought the widows of three civilians killed in an Air Force crash. Naturally, they requested military documents that would help prove negligence on the part of the Air Force. The goverment refused, saying that revealing the documents would divulge military secrets and harm national security. The court went along with it.
47 years later, the documents in question were finally declassified, and turned out to have no secrets or priviledged information at all! Instead,
"[the reports] were suffuse with information showing that there had been gross negligence with regard to the maintenance of the plane's engines, facts which would have likely been fatal to the Air Force's defense had it not been able to successfully conceal those documents by falsely claiming that national security would be harmed by disclosure."
The problem with this kind of privilege, of course, is that there is absolutely no way to verify it is justified. Imagine if Nixon had thought to invoke this on the Watergate case? Any information that is ruled a "state secret" has to be completely removed from the case if the case isn't just dismissed outright. It's like it didn't exist. As Richard Stiennon puts it, "How sweet it is to be in charge".