A high-end jewelry store is robbed at 10:00 PM on a Tuesday. The police have no witnesses and no usable security footage. However, they know that almost everyone carries a smartphone that constantly tracks location data via Google or Apple. Instead of naming a specific suspect, the police obtain a "Geofence Warrant." This warrant compels Google to provide the account identifiers of every single person whose mobile device was within a 500-foot radius of the jewelry store between 9:45 PM and 10:15 PM. After receiving a list of 50 sets of coordinates, the police narrow it down to three people who stayed in the area for more than 10 minutes. They then demand the personal identities of those three people. One of them, "Subject A," is found to have a prior criminal record. The police get a second warrant to search Subject A's house, find the jewelry, and arrest them. Did the Geofence Warrant violate the fourth amendment?

Kimi K2.5

Vote: Yes

The Geofence Warrant violates the Fourth Amendment's particularity requirement, which mandates that warrants describe the specific 'persons or things to be seized' with particularity. By casting a dragnet over every device within a 500-foot radius, the police conducted a general warrant—exactly the abuse the Fourth Amendment was designed to prevent—collecting sensitive location data from dozens of innocent individuals without individualized suspicion. Under *Carpenter v. United States* (2018), the Supreme Court held that warrantless access to historical cell-site location information violates the Fourth Amendment because such data reveals intimate details of life. While *Carpenter* specifically addressed cell-site data, its reasoning extends to precise GPS data from smartphones. More importantly, the Court emphasized that the Fourth Amendment requires probable cause and particularity, not just reasonableness balancing. Reverse warrants like this one invert the constitutional framework: instead of identifying a suspect and seeking evidence, police identify evidence and then search through private data of unknown persons to find a suspect. This 'fishing expedition' through the digital effects of innocent people—who have a reasonable expectation of privacy in their location history—constitutes an unreasonable search.

GPT-5.4

Vote: Yes

The geofence warrant likely violated the Fourth Amendment because it lacked particularity and resembled a digital general warrant. Instead of identifying a specific person or device based on individualized probable cause, it swept in every device within a 500-foot radius during a 30-minute window. That means the search began by collecting location data on many innocent people first, then worked backward to find a suspect. The Fourth Amendment is generally meant to forbid exactly that kind of broad, exploratory search. Location data is also highly sensitive. Modern Supreme Court doctrine, especially Carpenter, recognizes that historical cell-site and similar digital location tracking can reveal deeply private movements and associations. That makes indiscriminate collection more constitutionally suspect. The later narrowing process and second warrant do not cure the initial defect. If the first search was unconstitutional, the identities and evidence derived from it are potentially fruit of the poisonous tree. So even though the police eventually found the right person and obtained a later warrant, the original geofence warrant was too broad and insufficiently particular under the Fourth Amendment.

Grok 4.20

Vote: Yes

The Fourth Amendment prohibits unreasonable searches and requires warrants to show probable cause and particularity. A geofence warrant compels production of location data for every device in a broad area and time window, without any individualized suspicion for the dozens of innocent people affected. This functions like a digital general warrant, the very abuse the Fourth Amendment was written to prevent. Carpenter v. United States already recognized that cell-site location information is protected and requires a warrant for specific targets; expanding that to mass sweeps of non-suspects violates the same principle. Subsequent narrowing to three people and a second warrant does not cure the initial overbreadth. The geofence warrant itself was therefore unconstitutional.

Gemini 3.1 Pro

Vote: Yes

The Fourth Amendment explicitly requires that a warrant be supported by probable cause and "particularly describe the place to be searched, and the persons or things to be seized." A geofence warrant inherently fails this particularity requirement. Instead of targeting a specific, known suspect with established probable cause, a geofence warrant operates as a dragnet. It forces a tech company to search the location data of every single individual who happened to be in a given geographic area. This functions as a modern-day "general warrant"—the exact type of sweeping, suspicionless search the Founders drafted the Fourth Amendment to prohibit. By capturing the private data of dozens of innocent bystanders (the 50 sets of coordinates) without any prior individualized suspicion, the warrant constitutes an unreasonable search. Recent landmark rulings, such as the 5th Circuit Court of Appeals decision in *United States v. Smith* (2024), have confirmed that geofence warrants are fundamentally unconstitutional for these exact reasons.

Claude Opus 4

Vote: Yes

The Geofence Warrant violates the Fourth Amendment for several compelling reasons. First, the Fourth Amendment requires warrants to be supported by probable cause and to 'particularly describ[e] the place to be searched, and the persons or things to be seized.' A geofence warrant fundamentally inverts this requirement. Instead of identifying a suspect and then seeking evidence, it sweeps up data on every person in a geographic area — including dozens of entirely innocent people — and then works backward to find a suspect. This is the very definition of a general warrant, which the Fourth Amendment was specifically designed to prohibit. Second, the Supreme Court's landmark decision in *Carpenter v. United States* (2018) established that individuals have a reasonable expectation of privacy in their cell-site location information (CSLI), and that accessing such data constitutes a 'search' under the Fourth Amendment. The Court emphasized the 'deeply revealing nature of CSLI, its depth, breadth, and comprehensive reach, and the inescapable and automatic nature of its collection.' A geofence warrant implicates these same concerns — it compels disclosure of precise location data that people did not voluntarily share with law enforcement. Third, there is no probable cause to believe that any of the 50 people whose data was initially seized were involved in the crime. The warrant treats every person who happened to be near the store — residents, passersby, workers, diners at nearby restaurants — as a potential suspect. This dragnet approach lacks the individualized suspicion that probable cause demands. Fourth, in August 2024, the Fifth Circuit ruled in *United States v. Smith* that geofence warrants are categorically unconstitutional under the Fourth Amendment, finding them analogous to the 'general warrants' that the Founders sought to eliminate. While other circuits may differ, this represents the most thorough judicial analysis of the issue to date. The fact that the police eventually found the stolen jewelry does not retroactively justify the constitutional violation. The exclusionary rule exists precisely to prevent law enforcement from benefiting from unconstitutional searches. The jewelry evidence is fruit of the poisonous tree.

GLM 5

Vote: Yes

The Geofence Warrant violated the Fourth Amendment's particularity requirement. Traditional warrants must specifically describe the place to be searched and identify the person or items to be seized based on probable cause. Here, police had no individualized suspicion against any specific person—they instead conducted a dragnet search of 50 innocent people's location data to generate leads. This resembles the 'general warrants' and writs of assistance that the Fourth Amendment was explicitly designed to prohibit. The British Crown's use of general warrants to conduct broad, non-particularized searches was precisely the abuse the Framers sought to prevent. By compelling data on everyone within 500 feet, police reversed the constitutional order: investigating first, then developing suspicion. The Carpenter v. United States (2018) decision established that historical cell-site location information enjoys Fourth Amendment protection because it reveals intimate details of life. Obtaining location data for 50 unknown individuals—without probable cause as to any of them—constitutes an unreasonable search, even with judicial authorization. A judge's approval cannot cure a warrant's constitutional defects.

Final Summary

The AI Roundtable reached a unanimous verdict, with all six models—Claude Opus 4, Gemini 3.1 Pro, GPT-5.4, Grok 4.20, Kimi K2.5, and GLM 5—concluding that the geofence warrant was a clear violation of the Fourth Amendment. The group collectively argued that these 'reverse warrants' act as digital dragnets, sweeping up the private data of innocent bystanders to work backward toward a suspect, rather than starting with individualized suspicion.

No agreement after 1 rounds of discussion. Final vote: Yes: 6

Strongest Arguments

• Yes: The warrant violates the particularity requirement by inverting the constitutional order: instead of identifying a suspect and then seeking evidence, it conducts a mass search of innocent people to generate a lead, effectively reviving the 'general warrants' the Founders specifically sought to abolish.