In American Civil Liberties Union v Clapper, the United States Court of Appeals for the Second Circuit addressed head-on whether the National Security Agency’s (NSA) secretive bulk collection of every American’s telephone metadata was legal.

The court’s answer? The program is not lawful.

The court did not just rule the program unlawful; in its 97-page decision, the court gave loud and clear cues to Congress to reform existing intelligence-gathering legislation to both protect citizens’ privacy and still provide the government the necessary tools to gather critical information on terrorism.

Given the Fourth Amendment and our federal wiretapping legislation – both of which prohibit warrantless government surveillance of our electronic communications – a secretive collection of every American’s telephone call metadata unrelated to a targeted law enforcement investigation by the NSA would seem per se unlawful.

So how did something so seemingly simple and clear become so complicated?

The tension between national security and domestic security

The problem starts with the inherent tension between the executive branch’s power to protect national security on the one hand and to enforce domestic security on the other. The law regulates and restricts in very different ways the executive branch’s authority to engage in these two distinct activities.

To clarify: the NSA’s mass-scale-style telephone metadata collection was authorized by court order. The court that authorized it is the Foreign Intelligence Surveillance Court (FISC).

But until Edward Snowden’s 2013 revelations via The Guardian, FISC’s authorization of NSA’s bulk collection of telephone metadata was virtually unknown to the general public and to the majority of Congress because FISC typically operates and issues its orders in complete secrecy.

The creation and role of FISC

FISC was created when Congress enacted the Foreign Intelligence Surveillance Act (FISA) in 1978 to curb the executive branch’s “abuses” in foreign intelligence gathering that overflowed into domestic security and impinged on American citizens’ constitutional rights.

Thus, FISA regulates the government’s foreign intelligence surveillance-gathering activities for national security purposes, whereas Title III (also known as the Federal Wiretap Act) regulates the government’s domestic law enforcement activities.

In 1998, Section 215 was added to FISA by amendment. It allows the US government when gathering foreign intelligence to apply to FISC for court orders that require businesses to produce “business records.” Under Section 215, the government only has to make a minimal showing of why it needs the business records.

After the attacks of September 11 2001, the USA PATRIOT Act expanded FISA’s Section 215 to give the government the ability – upon approval by FISC – to demand production of “any tangible things” along with business records. Thus, under the 9/11 beefed-up version of Section 215, the NSA repeatedly has obtained renewed orders from FISC requiring the major telecommunications companies to turn over ALL bulk telephone metadata.

Section 215 was passed with a sunset provision, and Congress has renewed it seven times. But such repeated renewals should not be interpreted as Congressional approval. As carefully documented in the Second Circuit’s opinion, the vast majority of Congress was purposefully kept in the dark about the NSA’s program, and was completely unaware of how Section 215 was being interpreted by the government and applied by FISC to authorize the NSA bulk telephone metadata collection.

Section 215 is currently set to expire on June 1 2015.

Some observers say the Second Circuit’s ruling is merely symbolic because the court chose not to enjoin the NSA’s bulk collection, but rather pushed it back to Congress.

The court sets out a road map for Congress with a series of key cues

However, given the rapidly approaching June 1 deadline for Section 215 and the care taken by the Second Circuit to lay out a road map for Congress (the court even cited proposed legislation that would curb the use of Section 215), the Second Circuit may have chosen the more judicious and long-term answer.

Early in its lengthy opinion, the Second Circuit compared the NSA’s bulk telephone metadata collection in the name of “national security” and the public’s adverse reaction after Snowden’s revelations to the 1970s, when wide-scale executive branch foreign intelligence surveillance “abuses” were publicly revealed and spurred Congressional reform.

Let’s call this comparison of today’s situation to that of 1970s wiretapping scandals the Second Circuit’s first of many “cues” to Congress to take action.

Cue two to Congress

The Second Circuit defined “metadata,” noting that it reveals intimate information about individuals even when such data is de-identified; the court specifically cited addiction, suicide, crime, political and religious affiliations, social status and intimate relationships.

The plaintiffs and amici in ACLU v Clapper represented a broad coalition of privacy and civil liberty interests, all essentially asserting that the NSA program was unconstitutional on First and Fourth Amendment grounds and violated federal electronic surveillance laws.

The government presented myriad defenses, the more notable of which included: plaintiffs’ claims were impermissible because plaintiffs lacked standing, ie, that they had suffered no actual injury upon which to bring a claim; under Section 215, Congress specifically precluded judicial review of the program, in part due to its secrecy and because challenges to the program would severely disrupt the “sensitive field of intelligence gathering”; and because it is “eminently reasonable to believe that Section 215 bulk telephone metadata is relevant to counter-terrorism investigations.”

Cue three

The Second Circuit rejected the government’s standing argument: as it pointed out, due to Snowden’s revelations, plaintiffs’ telephone communications clearly were seized, and the seizure itself constituted an injury in fact under the Fourth Amendment.

Cue four

The court also rejected the government’s preclusion arguments, wryly pointing out that Congress could hardly have intended to preclude review of the NSA program under Section 215 when the vast majority of Congress had no idea that Section 215 was being used as a justification by the NSA to collect every single American’s telephone metadata 24 hours a day, seven days a week.

Cue five

Refuting the government’s “reasonable” and “relevance” arguments and citing the Oxford English Dictionary’s definition of “investigation,” the Second Circuit astutely noted: “Indeed, the government’s information-gathering under the telephone metadata program is inconsistent with the very concept of an ‘investigation.’” Congress, the court noted, clearly limited Section 215’s authority to “investigations” not just general threat assessments.

And, in fact, the Second Circuit’s careful opinion and road map may be leading Congress somewhere. About a week after the Second Circuit issued its May 7 2015 decision, the House passed the USA Freedom Act, which if enacted would prohibit the NSA’s bulk telephone metadata collection under Section 215.

Now it’s up to Congress to act

But Senate Majority Leader Mitch McConnell pushed for an extension of Section 215’s sunset provision, arguing that the passing the House’s bill would force our government’s intelligence gathering into “the dark.” Senator McConnell argues that this extension would permit the necessary time to allow the Senate to debate fully the House-passed USA Freedom Act and specifically Section 215.

Members of both parties and the public are fiercely debating the NSA’s program and the proposed legislation.

It looks like a Congressional showdown is looming. With the long Memorial Day weekend coming, it is unclear just how hot Congress will get.