April 5, 2019 1:59PM

A Pretextual Traffic Stop Should Require Sufficient Pretext

Several years ago, Atlantic writer Conor Friedersdorf asked Twitter “If you could add one Bill of Rights style amendment to the Constitution what would it be?” I responded “The Fourth Amendment and “we mean it.”

My answer may have been tongue-in-cheek, but quite seriously, the Fourth Amendment and its protections have been eroded by the Supreme Court precedents over several decades. As a result, the power of the police to intrude upon the lives of individuals has grown and they have taken advantage of that power throughout the country.

The Fourth Amendment reads:

“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place searched, and the persons or things to be seized.”

In plain English, the amendment should mean—among other things—that the police cannot stop (or “seize”) you on the street for no good reason. In the context of traffic stops, the Supreme Court held in Whren v. U.S. (1996) that the police had to have probable cause to believe the driver or vehicle is in violation of a traffic law. In the abstract, Whren makes perfect sense: If an officer observes a moving violation, he or she can stop a driver to address the issue.

In practice, however, Whren has provided virtual carte blanche for police to stop motorists due to innumerable traffic laws, many of which are vague and subjective, that most drivers violate every time they get behind the wheel. As I explained in my 2016 Case Western Reserve Law Review article “Thin Blue Lies,” police routinely use these myriad violations as pretext to stop motorists and investigate other crimes entirely unrelated to traffic safety. Officers understand if they follow any driver long enough, they can almost certainly find a pretext for stopping the vehicle and conducting an informal roadside investigation, subverting the spirit (if not the letter) of the Fourth Amendment’s protection against arbitrary seizure.

Despite this gaping hole in Fourth Amendment protections, police officers in Nebraska initiated a traffic stop on a vehicle without probable cause of any traffic violation whatsoever. (This isn’t hyperbole. In court filings, the State of Nebraska stipulates there was no traffic violation.) As a result of the stop, the driver of the vehicle, Mr. Colton Sievers, was questioned and eventually arrested for methamphetamine possession after a search of his vehicle. He moved to have the evidence thrown out because the original stop was an illegal seizure under the Fourth Amendment.

In a rather unusual decision, the Supreme Court of Nebraska found that the stop was legal under a different case, Illinois v. Lidster (2004), which allowed police to stop vehicles at checkpoint to seek eyewitnesses to a recent crime in the area, not to investigate drivers for criminal wrongdoing. The merits of that decision aside, neither Sievers nor the State of Nebraska argued Lidster would have permitted the stop at issue in the present case.

So unusual is the Nebraska Supreme Court decision that law professor Orin Kerr, to whom Cato scholars often find ourselves in opposition regarding Fourth Amendment jurisprudence, has joined the Sievers legal team and co-authored a cert petition to the U.S. Supreme Court (SCOTUS). The petition asks SCOTUS to either hear Sievers v. Nebraska or summarily reverse the decision below.

In a Volokh Conspiracy blogpost about the Nebraska Supreme Court decision, Kerr wrote:

It's true that Lidster allowed a suspicionless "information-seeking" checkpoint stop, which is effectively an exception to the usual rule that reasonable suspicion is required under Terry v. Ohio. [note: Terry v. Ohio (1968) preceded Whren, requiring police to have reasonable suspicion to initiate a pedestrian stop.] But the key to Lidster was that the officers were only trying to find innocent eyewitnesses to a past crime. The police set up the checkpoint at the scene of the accident hoping to find a member of the public who had seen the crime and might be able to give the police some leads. This fell out of the usual Terry requirement of suspicion, the Lidster Court held, because the police where just asking members of the general public if they could help the police.


It seems obvious that Sievers was different. This was not a case of "seeking information from the public." The officers testified that they stopped the truck because they thought it might contain evidence of crime -- specifically, stolen goods that they thought were being stored at the house where the truck had been parked. When the stop occurred, the officer who ordered the stop "advised the [other] officers to make a traffic stop to prevent the truck from leaving with any stolen items." The lead officer explained that they need to stop and search the truck "for any items taken from the [firearms] burglary."

And when Sievers was stopped, the officers didn't treat him like a member of the public who perhaps just might have seen a crime. Instead, Sievers was treated as a dangerous suspect.

Hopefully, SCOTUS agrees to hear the Sievers case or summarily reverses the Nebraska Supreme Court. SCOTUS has already ceded too much leeway to police to stop motorists as pretext, but police officers should at least meet the minimum standard for a legal stop.

You can read the whole cert petition here.

January 18, 2018 1:09PM

Fear and Mass Surveillance: Our Constitutionally Toxic Political Cocktail

At 12:51pm on January 18, 2018--just a day before it was set to expire--the Senate followed the House's lead and reauthorized the Foreign Intelligence Surveillance Amendments Act (FAA) Section 702 mass surveillance program for another six years by a vote of 65-34.

Writing for JustSecurity.org in October 2017, I made this prediction about the then-looming debate over extending the mass surveillance authority embodied in Section 702: 

Absent another Snowden-like revelation, Section 702 of the FAA will be reauthorized largely without change, and any changes will be cosmetic, and almost certainly abused. Whether it has a “sunset” provision or not is now politically and practically meaningless.

As it turns out, that prediction was optimistic. But first, a recap of the events of this week.

The real drama took place Tuesday evening, when Senate Majority Leader Mitch McConnell (R-KY) held open the procedural vote to end debate on the underlying Section 702 bill, S. 139, by some 90 minutes. The last two holdouts--John Kennedy (R-LA) and Claire McCaskill (D-MO) were worked over by anti- and pro-Section 702 forces on the Senate floor, with Senate Intelligence Committee Chairman Richard Burr (R-NC) calling in reinforcements in the form of Director of National Intelligence Dan Coats to help strong-arm Cassidy and McCaskill into voting to end debate on the bill. The pressure worked, with McCaskill providing the key vote to kill any chance of amending a bill that Senators Ron Wyden (D-OR) and Rand Paul (R-KY) declared was a direct threat to the Fourth Amendment rights of Americans.

Speaking after the procedural vote to kill debate on S. 139, Kennedy told reporters, "I was undecided when I walked on the floor, but the program expires Friday, and I don't want to play with fire. This is an important program."

Kennedy's "playing with fire" reference was a clear manifestation of the political fear he felt. After admitting he was undecided, he elected to be swayed by that fear--fear that the program would lapse without his vote. Fear stoked by the presence of DNI Coats, hovering just off of the Senate floor. Fear that if anyone died in a Salafist-initiated domestic terrorist attack in the period of time between the program's alleged expiration and renewal, he (Kennedy) would be blamed for it. His Missouri colleague, McCaskill, who is up for reelection this year in what will no doubt be a tough fight in a state Trump won in 2016, probably went through exactly the same things in her mind before casting the deciding vote to end debate and move S. 139 forward--with no chance to amend it. 

But would the Intelligence Community have have "gone dark" if the Senate had elected to continue debate beyond January 19 and allow amendments to the bill? No.

FISA Court orders issued under Section 702 are generally a year in length, which means that any orders issued prior to the technical legal expiration date would've been valid for another 12 months. Additionally, Section 702 is not the only authority under which the National Security Agency (NSA) can collect foreign intelligence information. Executive Order 12333, originally issued during the first Reagan administration, provides sweeping overseas intelligence collection authority that, at present, is not subject to any judicial review.

Indeed, it's EO 12333 that makes possible programs like RAMPART-A, as revealed in the Snowden Archive and reported by The Intercept in 2014:

It has already been widely reported that the NSA works closely with eavesdropping agencies in the United Kingdom, Canada, New Zealand, and Australia as part of the so-called Five Eyes surveillance alliance. But the latest Snowden documents show that a number of other countries, described by the NSA as “third-party partners,” are playing an increasingly important role – by secretly allowing the NSA to install surveillance equipment on their fiber-optic cables.

The NSA documents state that under RAMPART-A, foreign partners “provide access to cables and host U.S. equipment.” This allows the agency to covertly tap into “congestion points around the world” where it says it can intercept the content of phone calls, faxes, e-mails, internet chats, data from virtual private networks, and calls made using Voice over IP software like Skype.

Not surprisingly, Senator Burr failed to mention these facts during his pitch to his colleagues to renew the Section 702 program on Tuesday or today.

Also on Tuesday, Burr made the following assertions:

Let me just say from the start, this is the single most reviewed program that exists in the Federal Government. This is reviewed congressionally--it is reviewed by the courts, it is reviewed by the DNI, it is reviewed by the inspector general and the Department of Justice--because, on the committee, we realize this requires not just the stamp of approval from Congress but the assurance by the Intelligence Committee and by every branch of government that it lives within the parameters we set.

Let's examine each of these claims in turn.

Congressional review: Because House and Senate Intelligence Committee proceedings take place in secret, the public has no access to the committee hearing transcripts. We don't how exacting the questioning is, whether a committee had to employee a subpoena to get documents or witness cooperation, or what independent inquiries--like the Senate Intelligence Committee investigation into the CIA's torture program--have actually been conducted into Section 702 or any other program. This secrecy is only partly necessary. It should be possible to at least get declassified summaries of the issues and problems involving these programs that have actually been examined in depth without compromising any legitimately classified sources or methods. That we are not is a red flag.

FISA Court review: How effective is the FISA Court in preventing Fourth Amendment violations of Americans rights under the Section 702 program? Not very, as the activist group Demand Progress noted in a report issued in 2017. As the Demand Progress press release stated, "The report identifies overreaches by the Intelligence Community. These include Constitutional problems, unauthorized information collection, failure to comply with FISA Court orders, failure to provide notice to defendants, and mismanagement of acquired data."

Neither Senator Burr or any other Section 702 supporter referenced these violations during debate over S. 139.

DNI review: The DNI is a program proponent, not an objective overseer. DNI Coats' presence just off the Senate floor was designed to ensure ultimate passage of the underlying bill. Burr's assertion here does not pass the "laugh test."

IG review (including DoJ): The last Section 702 Department of Justice Inspector General compliance report was issued in 2012, and was only declassified in part due to litigation by the New York Times. Thus, the public has no idea whether additional compliance reports have actually been produced, much less what they've found. Moreover, recent reporting by investigative journalist Jenna McLaughlin at Foreign Policy raises disturbing questions about the very integrity of Inspector General offices across the Intelligence Community, including the Intelligence Community Inspector General office itself. Not only is Burr not on the letter requesting a Government Accountability Office (GAO) review of the allegations, he made no mention of the controversy during his remarks on Section 702 reauthorization.

The fact that Burr does not appear to be interested in ensuring that IC whistleblowers can come forward to safely report problems with Section 702 or other surveillance programs makes a mockery of his claims that any IG examination of Section 702 can be trusted.

I began this piece by noting that my prediction last October that Section 702 would be reauthorized with minimal or cosmetic changes had proved optimistic. The Brennan Center's description of the actual effects of S. 139 tell the tale:

When Congress reauthorizes Section 702 of FISA—a law intended to authorize surveillance of foreigners only—it should take the opportunity to shore up privacy protections for Americans. S. 139 does the opposite. It codifies the government’s practice of “backdoor searches” without any meaningful restriction. It also authorizes an expanded form of “abouts” collection. It thus leaves Americans’ privacy more vulnerable, not less. 

Burr and other Section 702 reauthorization proponents have also asserted that the program does not deliberately target Americans--that any communications of Americans swept up in Section 702 dragnet are "incidentally" collected. But there's nothing "incidental" about deliberately targeting people--including Americans at home or abroad--who use the Tor anonymity tool for online browsing--something NSA has been doing for at least a decade. And as the Section 702 "minimization" procedures approved by then-Attorney General Eric Holder in 2009 make clear, NSA can keep and analyze any domestic U.S. communications acquired that employ any form of encryption:

Extract of FISA Section 702 NSA minimization procedures

With the growing number of Americans utilizing apps like Signal, Wickr, and similar encrypted messaging apps, it means the total number of Americans NSA can target for simply using encryption to protect their privacy will grow.

And if NSA can't figure out for sure if you are, in fact, a U.S. citizen, they will target you until they can prove otherwise:

FISA Section 702 NSA minimization procedures extract 2

The bill the Senate just passed and that President Trump will sign makes all of these problems worse. It's another tragic example of the triumph of fear over liberty in the Digital Age. 


December 20, 2017 1:34PM

FISA “Reform”: The Surveillance Fear Mongering Campaign Ramps Up

The House GOP leadership must be at least somewhat worried about the prospects for passage of their Foreign Intelligence Surveillance Amendments Act (FAA) Sec. 702 bill, HR 4478, which the House Rules Committee will consider later today in an "emergency" session.

I say this because this morning, the House GOP leadership circulated a wanted poster-style flyer of a dead man: Haji Iman, the alleged ISIS deputy finance minister and second in command to ISIS leader Abu Bakr al-Baghdadi, who was killed in eastern Syria on March 25, 2016. The flyer puts the phrase "ISIS" in a huge font, just in case the reader wasn't getting the message.

Claiming that "Iman would still be plotting to kill Americans without Section 702," the flyer then makes an interesting admission: that the search for Iman "was ultimately successful based almost exclusively on intelligence activities under Section 702" (emphasis added).

Not only does the flyer provide no proof that Iman was planning attacks on the United States, it omits the fact that both the Iraqi and U.S. governments had previously claimed repeatedly that Iman had been killed—six times, in fact.

As I've noted previously, two other major post-9/11 surveillance programs—the illegal STELLAR WIND mass surveillance program, and the PATRIOT Act's Sec. 215 telephone metadata collection program—failed to stop a single attack on America. If it took the NSA two years to find Iman using Section 702 "almost exclusively" after claiming repeatedly the man was dead, it should raise major questions about the veracity of the official government (and now House GOP leadership) account of this incident and the effectiveness of the Section 702 program.

And then there's that tantalizing phrase—"almost exclusively."

The flyer admits that programs besides Section 702 were responsible for finally—allegedly—killing Iman. So Section 702 collection was not, apparently, a "but for" capability (i.e., but for Section 702, Iman would still be alive). How effective is Secton 702? We don't know. There's never been an independent, case-by-case audit of claimed Section 702 "successes" during the nearly 10-year life of the program. And the bill being considered by the House Rules Committee today does not call for such an audit.

What the flyer also doesn't say is that as written, HR 4788 would effectively expand warrantless surveillance under Section 702, including potentially against purely domestic targets. Given the abuses of the Section 702 program that have been exposed over the past several years, HR 4478 is an amazing statement of the contempt the House GOP leadership has for the Fourth Amendment rights of Americans.

November 18, 2016 2:47PM

The IRS Believes All Bitcoin Users are Tax Cheats

The Internal Revenue Service has filed a "John Doe" summons seeking to require U.S. Bitcoin exchange Coinbase to turn over records about every transaction of every user from 2013 to 2015. That demand is shocking in sweep, and it includes: "complete user profile, history of changes to user profile from account inception, complete user preferences, complete user security settings and history (including confirmed devices and account activity), complete user payment methods, and any other information related to the funding sources for the account/wallet/vault, regardless of date." And every single transaction:

All records of account/wallet/vault activity including transaction logs or other records identifying the date, amount, and type of transaction (purchase/sale/exchange), the post transaction balance, the names or other identifiers of counterparties to the transaction; requests or instructions to send or receive bitcoin; and, where counterparties transact through their own Coinbase accounts/wallets/vaults, all available information identifying the users of such accounts and their contact information.

The demand is not limited to owners of large amounts of Bitcoin or to those who have transacted in large amounts. Everything about everyone.

Equally shocking is the weak foundation for making this demand. In a declaration submitted to the court, an IRS agent recounts having learned of tax evasion on the part of one Bitcoin user and two companies. On this basis, he and the IRS claim "a reasonable basis for believing" that all U.S. Coinbase users "may fail or may have failed to comply" with the internal revenue laws.

If that evidence is enough to create a reasonable basis to believe that all Bitcoin users evade taxes, the IRS is entitled to access the records of everyone who uses paper money.

Anecdotes and online bragodaccio about tax avoidance are not a reasonable basis to believe that all Coinbase users are tax cheats whose financial lives should be opened to IRS investigators and the hackers looking over their shoulders. There must be some specific information about particular users, or else the IRS is seeking a general warrant, which the Fourth Amendment denies it the power to do.

Speaking of the Fourth Amendment, that rock-bottom "reasonable basis" standard is probably insufficient. Americans should and probably do have Fourth Amendment rights in information they entrust to financial services providers required by contract to keep it confidential. Observers of Fourth Amendment law know full-well that the "third-party doctrine," which cancels Fourth Amendment interests in shared information, is in retreat.

The IRS's effort to strip away the privacy of all Coinbase users is more broad than the government's effort in recent cases dealing with cell site location information. In the CSLI cases, the government has sought data about particular suspects, using a standard below the probable cause standard required by the Fourth Amendment ("specific and articulable facts showing that there are reasonable grounds to believe").

In United States v. Benbow, we argued to the D.C. Circuit that people retain a property right in information they share with service providers under contractual privacy obligations. This information is a "paper or effect" for purposes of the Fourth Amendment. Accordingly, a probable cause standard should apply to accessing that data.

Again, the government in the CSLI cases sought information about the cell phone use of particular suspects, and that is controversial enough given the low standard of the Stored Communications Act. Here, the IRS is seeking data about every user of Bitcoin, using a standard that's even lower.

Coinbase's privacy policy only permits it to share user information with law enforcement when it is "compelled to do so." That implies putting up a reasonable fight for the interests of its users. Given the low standard and the vastly overbroad demand, Coinbase seems obligated to put up that fight.

November 3, 2016 2:59PM

Communications and Data Meet the Fourth Amendment

This week and last, the Cato Institute filed amicus briefs urging the Supreme Court to take up two cases dealing with the constitutional status of "cell site location information," or "CSLI." This data, collected of necessity by cellular communications providers, creates detailed records of their customers' movements. The briefs invite the Court to accept these cases so it can revise Fourth Amendment practice to eschew doctrine and more closely adhere to the language of the Fourth Amendment.

The Fourth Amendment states that "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated." Presumably, when called upon to determine whether a Fourth Amendment violation has occurred, courts would analyze the elements of this language as follows: Was there a search? Was there a seizure? Was any such search or seizure of "their persons, houses, papers, [or] effects"? Was any such search or seizure reasonable?

And in cases involving familiar physical objects, courts usually do a sound textual analysis, at least implicitly. But in harder cases dealing with unfamiliar items such as communications and data, courts retreat to "reasonable expectation of privacy" doctrine that emerged from Katz v. United States in 1967, and offshoots of it like the "third-party doctrine." The "reasonable expectation of privacy" test asks whether defendants' feelings about things government agents accessed were reasonable. The corollary "third-party doctrine" cancels Fourth Amendment interests in information and things that are shared on the theory that expectations of privacy evaporate in that context.

The "reasonable expectation of privacy" test is the product of one non-essential concurrence in Katz, and the third-party doctrine was wrong when the Supreme Court created it in 1976 to ratify a law that deputized banks into financial surveillance. That doctrine grows further out of synch with each step forward our society takes in modern, connected living. Today, third-party service providers collect incredibly deep reservoirs of information about us: Cellular telephone networks, Internet service providers, search engines, and payment systems have data that can throw open windows onto our relationships, feelings, health conditions, business dealings, sexuality, emotions, and more.

In United States v. Carpenter, the U.S. Court of Appeals for the Sixth Circuit turned aside the appeal of two men convicted of armed robbery, whose CSLI had been used as evidence against them. Relying most heavily on an application of the "reasonable expectation of privacy" test in Smith v. Maryland, the court said that, while the contents of communications are protected by the Fourth Amendment, routing information is not. The court backhandedly dismissed the crucial question of whether the defendants had a property right in the data the government had seized, even though contracts and regulation both allocate property rights in data about communications use to consumers.

And in a similar case, Graham v. United States, the Fourth Circuit held that CSLI isn't constitutionally protected because "an individual enjoys no Fourth Amendment protection 'in information he voluntarily turns over to [a] third part[y]'" (quoting Smith v. Maryland).

Rather than relying on misshapen precedent as the appeals courts did, the Supreme Court should find that communications and data are items that can be seized and searched. Consistent with precedents both longstanding and recent, the Court should recognize that telecommunications customers can have property rights in such data, and that when the government seeks to seize and search such data, it generally requires a warrant. This will permit courts below to address seizures and searches of communications and data forthrightly, confidently assessing the reasonableness of government searches and seizures even when communications and data are involved.

The briefs join a merits brief filed this summer in United States v. Benbow, a CSLI case pending in the D.C. Circuit.

August 30, 2016 3:12PM

The Weird World of Data (and Your Privacy)

In 2007, Judge Richard Posner found it "untenable" that attaching a tracking device to a car is a seizure. But the Supreme Court struck down warrantless attachment of a GPS device to a car on that basis in 2012. Putting a tracking device on a car makes use of it without the owner's permission, and it deprives the owner of the right to exclude others from the car.

The weird world of data requires us to recognize seizures when government agents take any of our property rights, including the right to use and the right to exclude others. There's more to property than the right to possession.

In an amicus brief filed with the U.S. Court of Appeals for the D.C. Circuit last week, we argued for Fourth Amendment protection of property rights in data. Recognition of such rights is essential if the protections of the Fourth Amendment are going to make it into the Information Age.

The case arises because the government seized data about the movements of a criminal suspect from his cell phone provider. The government argues that it can do so under the Stored Communications Act, which requires the government to provide "specific and articulable facts showing that there are reasonable grounds to believe that [data] are relevant and material to an ongoing criminal investigation." That's a lower standard than the probable cause standard of the Fourth Amendment.

As we all do, the defendant had a contract with his cell phone provider that required it to share data with others only based on "lawful" or "valid" legal processes. The better reading of that industry-standard contract language is that it gives telecom customers their full right to exclude others from data about them. If you want to take data about us that telecom companies hold for us under contract, you have to get a warrant.

Under the "reasonable expectation of privacy" test, a person doesn't have privacy or a Fourth Amendment interest in information they share with others. But, as we pointed out to the appeals court, the Supreme Court has been moving away from the "reasonable expectation of privacy" test and its step-child, the "third-party doctrine."

The Court of Appeals should put aside doctrine and administer the Fourth Amendment like a law. If there was a seizure---an invasion of a property right, including the right to exclude others from data---that should be reviewed for reasonableness. And the hallmark of reasonableness is getting a warrant.

Speaking of administering the Fourth Amendment, the weird world of data is going to require a deeper understanding of what it means to "search," too. A new law enforcement technique uses advanced data collection and storage techniques to search entire communities before the government knows what it's looking for.

Since January, Baltimore police have been recording all activity in the city from above, using a special, camera-equipped plane. The data collected makes any visible activity available for police to review later. I'm calling it "pre-search," and I've written about it on the Reason blog.

In an ordinary search, you have in mind what you are looking for and you go look for it. If your dog has gone missing in the woods, for example, you take your mental snapshot of the dog and you go into the woods comparing that snapshot to what you see and hear.

Pre-search reverses the process. It takes a snapshot of everything in the woods so that any searcher can quickly and easily find what they later decide to look for.

In this case, it's not the woods. It's every home in Baltimore, and every Baltimorean. Even though the order may be backward, their interests in security from unreasonable search is the same. When this technique gathers information about people's movements and activities in and around homes, the government's collection and use of data should be subject to the Fourth Amendment's constraints.

Pre-search is in use at departments of motor vehicles around the country today. Many are using facial recognition to scan the faces of all applicants and drivers' license holders---and they're doing it without suspicion. Scanning the faces of every driver license holder is a pre-search that sets up innocent people for later digital searching.

The weird world of data gives us a lot to grapple with if we're going to protect our privacy.

August 28, 2016 7:03PM

The Fourth Amendment Protects Your Cell‐​Location Data

When the federal district court in D.C. ordered a seizure of Alonzo Marlow’s cell service location information (CSLI) held by his cell provider, it held that the federal government didn’t need a warrant to obtain CSLI data from a person’s phone provider. The Stored Communications Act of 1986 (SCA) governs the searching of such data, and under § 2703(d) of that act, federal investigators need not demonstrate probable cause in order to search—but merely to show “specific and articulable facts” that there is criminal wrongdoing. Thus, the Fourth Amendment requirement that “no warrants shall issue, but upon probable cause” is effectively removed.

Cato has filed an amicus brief with the U.S. Court of Appeals for the D.C. Circuit, supporting the appeal of Marlow and his co-defendants. For purposes of the Fourth Amendment, cell phone data is a “paper” or “effect” in which there is a right of the people to be secure. The Supreme Court made clear in Riley v. California (2014) that giving police carte blanche to search a phone incident to an arrest would “in effect give police officers unbridled discretion to rummage at will among a person’s private effects.”

Indeed, Marlow specifically protected his cell data from prying eyes through his user agreement; Sprint was contractually obligated to maintain his privacy unless some valid lawful process required production. Because the government took Marlow’s data without his consent, there was a seizure of “effects” under the Fourth Amendment. But the district court did not issue a warrant for this seizure, instead simply acceding to the government’s § 2703(d) request.

The government claims that the SCA created the lawful process that satisfies the contractual exemption, so Marlow is out of luck. But in order for that process to be valid, it needs to comport with the Fourth Amendment.

When there is a property right to exclude others—which in this case was contractually created—the Fourth Amendment requires a probable-cause warrant, a higher standard than “specific and articulable facts.” Thus the SCA court order process itself is constitutionally infirm. The aim of the courts in interpreting the Fourth Amendment is to “assur[e] preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” Kyllo v. United States (2001).

Allowing the warrantless search of CSLI violates privacy as much as rummaging through a person’s physical papers did in 1776. To handle the challenges of the digital age, Fourth Amendment jurisprudence requires robust protection of cellular data contents as “effects.”

We urge the D.C. Circuit to reverse the ruling below in United States v. Benbow and make clear that property interests in data privacy are protected under the Fourth Amendment.