Congressional debates about the renewal of one of the United States’ most sweeping intelligence surveillance laws are heating up. Helping to shape the discussion are several newly released government documents that highlight the need to ask hard questions about all of the reasons the executive branch may be gathering private communications through warrantless surveillance. Some of the new information the documents provide reinforces our understanding of just how broad US warrantless intelligence surveillance is—and suggests how extensively this monitoring may be undermining fair trial and other rights.

On April 19, the Office of the Director of National Intelligence released a new question-and-answer document, which describes previously undisclosed specific examples of the executive branch using surveillance under Section 702 of the Foreign Intelligence Surveillance Act (FISA). Just days later, the Intercept published a 2015 amicus curiae brief and transcript from the FISA Court, which emphasized just how expansive Section 702 monitoring is and how easily (and potentially illegally) the FBI can search through this data . While the ODNI’s document highlights the use of Section 702 for counter-terrorism purposes and to monitor foreign governments, both the amicus brief and the transcript indicate that the government is using data from the programs under this law for reasons that go far beyond the ones the government is trumpeting. These and other declassified and leaked materials inspire concern that the executive branch may be using its vast warrantless powers in this area to detect low-level or routine offenses—including, for example, as part of the “War on Drugs.”

The potential for the government to use these immense, intrusive powers for counter-narcotic purposes in particular is even more disturbing in light of recent statements by Attorney General Jeff Sessions and other members of the Trump administration, who are taking a tough public posture on drug enforcement, including marijuana violations. I’ll return to that a little later, but first a little background information on Section 702.

Adopted in 2008, Section 702 allows the intelligence agencies to “target” non-US persons overseas for warrantless telephone or Internet monitoring. (“United States person” is a term of art that includes US citizens, green card holders, and some corporations and associations.) Although the agencies cannot deliberately “target” US persons, they believe they are entitled to vacuum up what the FISA Court’s newly published independent amicus describes as a “potentially very large and broad” number of Americans’ communications “incidentally .” Heightening concerns about the scale of this snooping, at least one Section 702 program that has been publicly acknowledged, known as “upstream” scanning, appears to be enormous. It allegedly involves automated searches of virtually all of the communications that flow over the Internet infrastructure that links the US to the rest of the globe. Another Section 702 program, PRISM, enables the NSA (with the FBI’s help) to demand communications from such major US Internet companies as Google, Apple, and Facebook.

The Office of the Director of National Intelligence has failed to answer repeated bipartisan requests from Congress for information about the number of US persons the government is spying on through these programs. However, when the Washington Post evaluated 160,000 e-mails and instant messages the agencies had gathered under Section 702, it found that 90 percent of the account holders were not the foreign “targets” of this surveillance and that “[m]any of them were Americans.”

The reasons for which the agencies can gather private communications under Section 702 are very broad. The government only needs to certify that “a significant purpose” (not necessarily the main purpose) of its monitoring is to obtain “foreign intelligence information.” That expansive description covers, among other things, any information about a foreign territory that “relates to” the “conduct of the foreign affairs of the United States.” (The ACLU has previously suggested that “[t]he government’s targets may even be entire populations or geographic regions,” although the government has contested this.)

The FBI may then conduct warrantless “backdoor searches” of the data it’s gathered without a warrant, even if—as the then-chair of the Privacy and Civil Liberties Oversight Board testified before Congress—it has “absolutely no suspicion of wrongdoing.” (During the FISA Court hearing, Amy Jeffress, the author of the independent amicus brief, characterized these FBI backdoor searches as “virtually unrestricted” and illegal.) The Bureau also has extensive powers to distribute Section 702 data to federal, state, local, or tribal law enforcement bodies, including if the data may contain evidence of a “crime.” Not just a terrorism-related crime or serious crime, but, as Jeffress stressed in her brief, any crime at all.

All of this brings us to the domestic drug war and the harmful potential impact of warrantless intelligence surveillance on the criminal justice system.

As Human Rights Watch and other experts have documented, the failed, decades-long, law enforcement-centered drug war has had devastating consequences for human rights. Increasingly, Americans appear to agree, taking steps to decriminalize and even legalize marijuana in several states and telling pollsters that treatment-centered approaches are better than those focused on prosecution—including for drugs such as heroin and cocaine that pose a more significant public health risk.

Yet, there are good reasons to be concerned that the federal government may be using its powerful Section 702 surveillance authorities to ferret out and prosecute ordinary drug crimes.

Although it seldom comes to the public’s attention, there is a decades-long relationship between US intelligence surveillance and the drug war. Executive Order 12333, another warrantless intelligence surveillance authority, has explicitly allowed the government to conduct surveillance on US persons without a warrant in the course of international drug investigations since the order was first issued in 1981.

Declassified documents from the early 1980s suggest that the NSA has long been providing data from its communications surveillance as part of counter-drug initiatives. The documents also show that the CIA was authorized to share drug-related intelligence under the executive order —including about US persons—with federal officials for law enforcement purposes.

Where Section 702 is concerned, two of the slides included in the documents leaked by former NSA contractor Edward Snowden indicate that the NSA has combed through its apparently large cache of PRISM data to produce reporting on “[n]arcotics” in Mexico and “[t]rafficking” in Colombia, while another slide from the same series shows that drug-related PRISM reporting was increasing as of 2012. Add to that the NSA’s relationship-mapping capabilities as well as the Defense Department’s view that “activities inside the United States that are directly tied” to overseas drug production or trafficking count as “international narcotics activities,” and it requires little imagination to see why people in the US might be caught in a warrantless drug-related dragnet—either because someone in their circle of relationships has been targeted or due to later “backdoor” querying. In the newly published transcript, the government itself points to the possibility that the FBI could search through Section 702 data while investigating “a minor crime like something like cigarette smuggling” (ostensibly on the off chance that such a minor crime might be connected in some way to terrorism).

If the government were in fact using warrantless intelligence surveillance to try to find people who may have committed low-level offenses, whether drug-related or otherwise, the public and even most members of Congress would not necessarily know. Despite a requirement in FISA that the government must notify criminal defendants when it intends to use evidence “obtained or derived from” Section 702 monitoring in legal proceedings, the Justice Department seems to have embraced a set of questionable definitions, policies, and practices to let it duck this obligation. For example, it has never disclosed how it interprets “derived from,” and may be using a practice known as “parallel construction” to invent alternative explanations for how it found information that, in reality, originally came from Section 702 surveillance.

This leads to the Kafkaesque prospect of convictions that are based partly on secret evidence that defendants have not had the chance to challenge as unconstitutional, unreliable, or incomplete.

In human rights terms, there are several fundamental problems with the use of a powerful, warrantless data firehose to detect ordinary crimes. First, as a general matter, government surveillance does not comply with human rights if it is arbitrary—and it is difficult to think of something more arbitrary than wholesale “upstream” scanning (as we currently understand it) or any program that results in a huge amount of supposedly “incidental” collection.

Second, the prevailing human rights norms require surveillance to be subject to judicial or other independent authorization to prevent abuses. A system that allows law enforcement to “poke around” for evidence of a crime without a judge’s sign-off is one that is ripe for misuse. Under international human rights treaties, criminal defendants are also entitled to a fair hearing, which would be jeopardized by the deliberate concealment of evidence obtained through potentially illegal surveillance.

Section 702 is scheduled to expire on Dec. 31 unless Congress renews it. This means Congress has an opportunity to enact reforms that would—at a minimum—address the worst ways the law violates or threatens to violate fundamental rights. These reforms should include, among others: strictly limiting the purposes for which the US intelligence agencies may conduct secret surveillance, strengthening judicial authorization and oversight, ending the apparently massive automated “upstream” searches, banning “backdoor” querying without a warrant, and imposing firm requirements for the government to notify criminal defendants if it has employed intelligence surveillance in an investigation in any way.

US surveillance should not overreach, nor should it pose a constant risk of arbitrary, systematic, or secret harm. Those kinds of abuses are some of the most important things the US Constitution—and the human rights treaties—were intended to prevent. Congress should act accordingly.

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