Nevada quietly signed an agreement earlier this year with a company that collects location data from cellphones, allowing police to track a device virtually in real time — all without a warrant. 

The software from Fog Data Science, adopted this January in Nevada through a Department of Public Safety contract, pulls information from smartphone apps in order to let state investigators identify the location of mobile devices. 

The state is allowed more than 250 queries a month using the tool, which allows officers to track a device's location over long stretches of time and enables them to see what Fog calls "patterns of life," according to company documents from 2022. It can help them deduce where and when people work and live, with whom they associate and what places they visit, according to privacy experts. 

Although Fog Data says that their data is made anonymous and "linked to devices … not people," the company says the tool can help access information that "would otherwise remain hidden." The company has a tool on their website that allows individuals to opt out of their databases. 

Privacy experts have raised concerns about violations of due process and the Fourth Amendment, which protects against unreasonable search and seizures. Traditionally, police must obtain a warrant from a judge to access cellphone location information — a process that can take days or weeks.

And while cellphone users may be aware that they are sharing their location through apps such as Google Maps, critics say few are aware that such information can make its way to police.

Because of the contract's low price tag (about $12,000 per year), it appears to have eluded public discussion. It only needed to be signed off by a state clerk, circumventing the typical approval process for major contracts that require sign-off from the governor, secretary of state and the attorney general. It is also entirely funded by a recently awarded federal grant. 

"It's alarming," Jacob Valentine, a staff attorney at the American Civil Liberties Union of Nevada, said in an interview. "I think there's more and more attempts to track where we are at all times and circumvent the warrant process."

It also comes as there has been increasing discussion about lack of guardrails around surveillance technology in Nevada, especially as political tensions heighten. In March, Democratic Nevada Attorney General Aaron Ford signed onto a letter calling on Congress to regulate use of data broker information, while several state lawmakers have expressed concerns about lack of regulation around automated license plate readers — another mass surveillance tool — which are present in every major city in the state. 

Still, the software has been promoted as a tool to bolster public safety, especially by cash-strapped law enforcement agencies. The Nevada Department of Public Safety, an umbrella agency that includes the Nevada State Police, has faced chronic staffing shortages for years. Its investigative unit — which was awarded the contract — works on counterterrorism efforts and coordinates with local, state, federal and tribal law enforcement as well as private sector stakeholders to analyze criminal information. 

Police in other states have said the technology (and its low price tag) has helped expand investigatory capacity, and they've  used the technology in murder investigations and to even track the movements of a potential participant in the Jan. 6 insurrection. 

In response to questions from The Nevada Independent, officials from the Nevada Department of Public Safety said they will use the tool to enhance information collection and threat-based analysis as well as to assist with criminal and terrorism-based investigations. They added in a statement that in order to maintain operational security, the department is "unable to provide specific tactical information." 

They did not answer questions about privacy concerns or what apps Fog is pulling data from. Asked about accountability measures for the software, a spokesperson for the agency said that "use of the product follows agency procedures and internal controls for computer access, confidentiality of information and case management."

How does it work? 

One way Fog acquires its data is by collecting it from apps that resell a user's location to third-party advertisers or data brokers. Specifically, it follows devices through something known as an advertising ID, a unique number assigned to devices in order to target ad content. These numbers do not contain the name of the phone's user, but can be traced to homes and workplaces. 

Just a single query in Fog gives authorities access to a treasure trove of data. There are two types of searches in the database. The first lets an officer look up a specified device, while the second option returns all cellphone location signals in a given area, according to a 2022 investigation from the Electronic Frontier Foundation, a nonprofit focused on digital rights and privacy. 

The Nevada Department of Public Safety's contract allows the agency to make more than 250 queries per month — something that raised red flags for Beryl Lipton, a researcher at the Electronic Frontier Foundation.

"You can cover a lot of ground with 250 queries," Lipton said. "One of the big concerns is that law enforcement would be able to vacuum up or have access to information about people who are nowhere near involved with anything that they're investigating." 

Lipton said it is not "unheard of" for the federal government to pay for this type of software. Local governments have been incentivized to sign up for Fog because of its low price tag and Lipton said that such deals can go through an entity like the Department of Homeland Security — which also handles federal emergency management — because it can be used as a tool to locate people lost in a natural disaster or similar catastrophe. 

"To be honest, I don't really know how that plays out," she said. "I don't know exactly how effective it is in an emergency." 

Concerns

John Piro, a public defender at the Clark County Public Defender's Office, called the use of the technology "unconstitutional." He didn't just express concern about how the technology could be used in criminal cases, but against everyday people.

"Just because you choose to navigate with an app like Waze doesn't mean you consent to the government being able to see all of your movements," he said in an interview. 

Piro pointed to a landmark Supreme Court case from 2018, Carpenter v. United States, where the court determined that gathering detailed cell location data constitutes a search under the Fourth Amendment and would thus require a warrant. He said that even if Nevada has no laws addressing the technology, it should not be used per that decision. He said that the technology makes "everyone a suspect." 

"Imagine you're driving and a murder had occurred on a roadway … but now your cellphone pings in that area," he said. 

In 2020, something like that did happen. The information of more than 1,600 people was released after California police pulled the cellphone location of a Nevada resident who was charged with murder-for-hire. It prompted a ruling from a Nevada federal court judge who decided that pulling large quantities of private personal data from cell towers is unconstitutional. She ultimately determined that the officers who pulled the data were acting in good faith, however.

Other agencies in Nevada have been known to use technology similar to Fog. In 2013, Las Vegas Metropolitan Police Department acquired something known as a cell-site simulator that mimics cellphone towers and can sweep up signals from entire areas to track individuals, with some models capable of intercepting texts and calls. Police have not released detailed information about the technology since then. 

Lipton also said she's worried about the technology being used to track protesters or people exercising their First Amendment rights. She said that it could be very easy for officers to search an area where a protest occurred and trace cell data back to locations such as homes. 

"If there aren't clear audit mechanisms that are being used, then there are lots of opportunities to be abused," Lipton said.