"We are glad the judge appears to be skeptical of the government's argument that no court can consider the legality of the NSA's program," said Ann Beeson, the associate legal director of the ACLU.

Judge Diggs may ultimately agree that she can't hear the suit, or the government may head to the court of appeals to seek dismissal before the June 12 hearing. The government has had some success invoking national security to avoid judicial inquiry into the legality of the NSA's spying program.

The government has succeeded in two recent cases to block lawsuits against its tactics in the war against terror by using the so-called state secrets doctrine, which provides the government a privilege against legal action if that action would diminish national security.

Once rarely used, the doctrine is now routinely wielded by the Bush administration, which is expected this month to intervene in some 20 cases filed against telephone companies that may have shared data on patterns of telephone calls with federal officials.

For now, at least, there's a chance that Judge Diggs won't blindly accept the argument that national security concerns override NSA's obligation to obey the law or the judicary's obligation to act as a check against the executive's lawless behavior.