The Supreme Court is set to decide tomorrow whether it will hear a case concerning criminal defendants' right to see surveillance applications approved by the secret FISA court. The case , United States v. Daoud, has broad implications for the constitutional rights of all Americans.

In September 2012, following an FBI sting operation, Adel Daoud was charged with attempting to use a weapon of mass destruction and attempting to damage and destroy a building using an explosive. The government notified Daoud that it intended to present evidence at his trial "obtained and derived" from surveillance conducted under the Foreign Intelligence Surveillance Act (FISA). This was not unusual in itself. In the years after FISA was enacted in 1978, FISA evidence turned up in criminal cases only very rarely. More recently, however, the government has been using FISA much more aggressively, including in criminal investigations.

What made Daoud's case unusual – indeed, unique – was that the judge presiding over the case ordered the government to disclose to defense counsel the secret court applications and orders that had authorized Daoud's surveillance. The order was both appropriate and constitutionally necessary, but the 7th U.S. Circuit Court of Appeals reversed it. Daoud's lawyers, joined by lawyers from the ACLU, have now asked the Supreme Court to reinstate the disclosure order.

As we wrote in the petition to the Supreme Court , the case raises a crucial question: When does the Constitution require that a criminal defendant be afforded access to the affidavits, applications, and warrants that were the basis for the government's surveillance of him?

Secret Surveillance Applications

When the government intends to conduct FISA surveillance, it applies to the Foreign Intelligence Surveillance Court for an order, similar to a warrant, authorizing such surveillance. The government has to show that there is probable cause to believe that the target of its surveillance is a foreign power or an agent of a foreign power. If the government ultimately ends up prosecuting the target of its FISA surveillance, it is required by law to notify the defendant whenever it intends to rely on information obtained or derived from that surveillance.

In theory, a defendant who has been notified of FISA surveillance can challenge the constitutionality of the surveillance – and demand that evidence derived from the surveillance be suppressed. The problem for defendants, though, is that they are completely in the dark about the evidence that the government relied on when it applied to the FISA court. Information cited in the government's FISA applications could have been false or misleading, or it could have come from other surveillance programs whose constitutionality is questionable at best. But without access to FISA applications and orders, defendants are unable to determine precisely which surveillance authorities were used against them, let alone whether those authorities were lawfully used.

The result is that it is impossible for many defendants to exercise their Fourth and Fifth Amendment rights to seek to suppress the fruits of unlawful surveillance. In Daoud's case, there are reasons to believe that the government obtained FISA warrants on the basis of evidence derived from the FISA Amendments Act of 2008 , a statute that the ACLU and others have argued is unconstitutional. Without access to the government's FISA materials, though, Daoud can't know what role the FISA Amendments Act of 2008 played in the government's investigation of him, and he can't bring an informed challenge to the constitutionality of the government's surveillance.

Since FISA was enacted in 1978, courts have struggled to reconcile the statutory limits on disclosure with criminal defendants' rights under the Fourth and Fifth Amendments, which guarantee a meaningful opportunity to seek the suppression of illegally obtained evidence. The resolution of this tension is crucial to criminal defendants, for obvious reasons.

But it is crucial to the rest of us, too, because the fact that criminal defendants like Daoud cannot meaningfully exercise their constitutional rights creates a structural problem. The government does not ordinarily notify those whose communications it has monitored under FISA or other national security authorities, and so the vast majority of those whose privacy is implicated by national security surveillance lack the ability to challenge its lawfulness. The only people who ever learn that they've been monitored under these authorities are criminal defendants.

As a result, motions to suppress in criminal prosecutions are the principal means, and in many contexts the only means, through which the constitutionality of certain government surveillance programs is tested. When criminal defendants are denied access to materials that would allow them to challenge the lawfulness of this surveillance, the surveillance is shielded from judicial review – and effectively placed beyond the reach of the Constitution.

As we argued in our petition for review, Daoud's case raises an important constitutional question that warrants the Supreme Court's attention. We're hopeful that the court will grant the petition.