Leaking Illegal Government Action: Illegal?

I'm no lawyer, so could someone who's qualified, enlighten me? When Bush's Attorney General starts going after the officials and reporters who leaked Warrantless Wiretaps, aren't they shooting themselves in the foot?

Assume for a moment the Justice Dept. actually charges someone for leaking the Warrantless Wiretap program (I refuse to call it "Terrorist Surveillance Program"). If I were the defense attorney, my first questions would have to be:

Is it illegal to release information regarding government actions of questionable legality?

Isn't it an official duty to expose illegal government activity? After all, it is a soldier's duty to refuse an illegal order. That was proven by the Nuremburg Trials after World War II.

The Administration, by charging someone with this "leak", is asking for a court test of the legality of their own actions. In my mind, given our current laws, Warrantless Wiretaps on US citizens are patently illegal. The Administration may jam a law through Congress making it legal, but, that would not "grandfather" in earlier, illegal actions. Thus, "leaks" on this subject are simply the actions of conscientious "whistle-blowers."

If Mr. Bush and his shill, the Attorney General, want to shoot themselves in the foot, wouldn't it be simpler to go hunting with Cheney?