In a world of electronic surveillance and secret searches, notice is more essential than ever. Notice allows criminal defendants to test whether the government’s evidence was, in fact, obtained lawfully, which is a right fundamental to due process. And, after Clapper v. Amnesty, notice to defendants is one of the few mechanisms by which dragnet surveillance programs—which affect millions—will ever be reviewed in court. But is the government providing notice when it should be?

It seems not. In the brewing battle over surveillance conducted pursuant to Executive Order 12333, there is yet another test of this crucial issue—one that comes on the heels of the government’s admitted failure to comply with notice requirements in the context of surveillance conducted under the FISA Amendments Act. The government has never publicly disclosed how it views its notice and due process obligations when it comes to E.O. 12333. That secrecy alone is troubling—which is why the ACLU has filed a FOIA request to compel the government to disclose its policies, guidance, and legal analysis. Shouldn’t courts and the public know where the government believes its duty to give notice starts and ends?

And there’s good reason to ask questions. A new story by Charlie Savage in the New York Times suggests the government has interpreted its notice obligation exceedingly narrowly. In fact, it appears that the Justice Department believes there is a foreign-intelligence exception to the usual Fourth Amendment requirement that the government give notice of “derived” evidence in criminal cases, at least for surveillance under E.O. 12333. As the Times reports:

In practice, officials said, the government already avoids [introducing evidence obtained directly from 12333 intercepts], so as not to have to divulge the origins of the evidence in court. But the officials contend that defendants have no right to know if 12333 intercepts provided a tip from which investigators derived other evidence.

So, in short, the government believes it must give notice when it uses evidence obtained directly via E.O. 12333 surveillance—which it assiduously avoids doing—but that it need not give notice where its evidence is simply “derived” from an E.O. 12333 intercept.

Sound familiar? If it does, it’s because this is the same theory that National Security Division lawyers offered to Solicitor General Verrilli when they were confronted about misleading statements the government had made concerning notice of surveillance conducted under the FISA Amendments Act, as Savage reported last October. It’s a theory that the government has since abandoned when it comes to the FISA Amendments Act—reportedly because the Solicitor General ultimately concluded that the theory “could not be justified legally.”

One can now surmise that Verrilli prevailed in that debate on statutory, not constitutional, grounds. FISA expressly requires the government to provide notice of evidence “obtained or derived” from electronic surveillance. The statute applies that requirement to traditional FISA surveillance as well as to surveillance conducted under the FISA Amendments Act. No similar statutory notice requirement, however, applies to surveillance conducted under E.O. 12333. If the government is not providing notice of E.O. 12333 surveillance, it is likely because DOJ has concluded the Constitution does not require it.

That conclusion is significant—and deeply suspect—for at least five reasons:

(1) What it says about DOJ’s view of the Fourth Amendment right to notice. The Fourth Amendment requires notice of a search whether the government’s evidence is obtained or derived from that search. This principle is essential to any meaningful application of the “fruit of the poisonous tree” doctrine, which permits a defendant to suppress evidence derived from an unlawful search. Without telling anyone—let alone any court—DOJ has apparently granted itself an exception to this basic rule of notice in the context of foreign-intelligence surveillance.

(2) What it means for the due process rights of criminal defendants. Without notice of “derived” evidence, defendants prosecuted with the help of E.O. 12333 surveillance may have no opportunity to challenge the legality of the government’s investigation.

Yet, as we know, E.O. 12333 surveillance is not overseen by any court, and today it involves some of the most novel, intrusive, and massive surveillance techniques ever used by the government. If the government is not providing notice in certain circumstances, it is depriving criminal defendants of a due process right the Supreme Court has long found fundamental.

(3) What it means for criminal investigations. A rule that does not require notice of “derived” evidence encourages government agents to routinely engage in parallel construction—that is, to launder evidence procured using E.O. 12333 so that it appears the evidence was obtained using some other, less controversial means. As the Times article suggests, that may be exactly what FBI and DOJ often do when officials say the government “avoids” using evidence obtained directly under E.O. 12333.

(4) What it means for judicial review of dragnet surveillance programs. If the government can always avoid giving notice of E.O. 12333 surveillance, then it may be able to perpetually avoid judicial review altogether. Today, “standing” is an immense obstacle for ordinary citizens who seek judicial review of controversial spying programs, even where those programs affect millions. In Clapper, the Supreme Court indicated that notice to criminal defendants would ensure that there was some path to judicial review of the FISA Amendments Act. Not so, it appears, with E.O. 12333 surveillance. Has DOJ invented, in essence, a foreign-intelligence exception to judicial review? Or does DOJ’s no-notice policy mean civil plaintiffs have standing to challenge E.O. 12333 surveillance in the courts?

(5) What it shows about the fundamental dangers of secret notice policies. When the government formulates and applies a notice policy entirely behind closed doors, it embraces one of the most impenetrable forms of secret law. That is because the people it deprives of notice will never know that the government chose not to provide notice to them. This is the notice paradox. How can a criminal defendant challenge a search he doesn’t know about, which the government hides from view based on a notice policy he doesn’t know about? Notice, in other words, is an extremely difficult right for individual defendants to enforce, unless the government is transparent about how it interprets that obligation.

The government has no legitimate interest in keeping its view of its notice obligations from the public or defendants. It can only serve to insulate from public and judicial scrutiny a cramped and unjustifiable view of what is a core constitutional obligation.