Stingrays: A “Legal Gray Area” and How Law Enforcement Can Violate Your Fourth Amendment Rights

Introduction to Stingrays

Stingray devices, also known as “Mobile Device Identifiers” (MDIs) or “IMSI catchers,” are intrusive cell phone surveillance devices.[1] They operate by mimicking cell phone towers and dispatching signals to cell phones within a certain radius, and in turn, the cell phones transmit their locations and other identifying information.[2] The issue with these devices is the method by which they obtain information that is then utilized by law enforcement. When used to track a suspect’s cell phone, these devices not only gather information from the suspect’s phone, but they also collectively circumvent data and information from the cell phones of countless innocent bystanders that are within the vicinity.[3]          

The Fourth Amendment to the United States Constitution aims at protecting people’s right to privacy and freedom from unreasonable intrusions by the government.[4] It does not protect against all searches and seizures within the confines of one’s home, but it certainly guarantees protection from those that are done by the government and deemed unreasonable by law.[5] When law enforcement utilizes Stingray devices in the course of investigating an identified suspect, for whom they had warrant and authority to obtain information, the Stingray device simultaneously picks up and collects private and confidential information of other individuals in the area, for whom law enforcement had no such warrant to obtain.[6] Thus, the utilization of  Stingray devices by law enforcement agencies tends to infringe upon the Fourth Amendment Constitutional rights of Americans.

This article critiques law enforcement’s Constitutional violations through its use of Stingray devices. Part II explains how Stingray devices work and how intrusive they can be with a case study of United States v. Rigmaiden. Part III explains why this is considered a “legal gray zone” and dissects governmental agencies’ improper use of Stingrays, included during Black Lives Matter protests in recent years. Finally, Part IV concludes by reasserting that law enforcement agencies use of Stingrays is unconstitutional and calls for action from lawmakers and politicians.

How United States v. Rigmaiden Shed Light on the Intrusive Nature of Stingrays

            When modern cell phones use a carrier’s network, cell phone towers with the strongest signal ping the cell phone’s location using GPS technology.[7] Cell phone companies store this GPS information, along with other data.[8] Law enforcement is required to obtain warrants whenever they wish to access this information, and when the warrant is approved, they are able to utilize the GPS technology to track suspects in real-time.[9] This method of tracking usually allows law enforcement to narrow a suspect’s phone location to within twenty to thirty meters.[10] Sometimes this is not specific enough, and that is where Stingray devices come in to help close the geolocation gap.

Daniel Rigmaiden first brought the federal government’s use of Stingray’s to the public’s attention.[11] In 2008, the government suspected Rigmaiden of being involved in a tax fraud scheme and requested a federal judge to order cell provider Verizon to assist in locating the defendant.[12] The government received an order telling Verizon to provide the location information of an Aircard that was believed to be the defendant’s, but the government interpreted this order as an authorization that somehow permitted its use of a Stingray in tracking down Rigmaiden.[13]

In United States v. Rigmaiden, defendant Rigmaiden was indicted on several counts of mail and wire fraud, aggravated identity theft, and conspiracy.[14] The government had located and arrested him by tracking the location of an Aircard connected to a computer that was allegedly used to perpetrate the fraudulent acts.[15] Rigmaiden only used fake identities and anonymous web browsing, so he could not understand how the government was able to track him using the Aircard.[16]

Rigmaiden decided to represent himself in the case, and while in prison, he requested and read through thousands of documents pertaining to his case to attempt to decode how the government tracked the Aircard.[17] After years of investigating, he put together enough proof to get a sense of what Stingrays are and how law enforcement uses them.[18] He then contacted the ACLU’s Christopher Soghoian, who helped to project to the public Rigmaiden’s findings on Stingrays and law enforcement's use of them.[19]

Rigmaiden alleged that the technology used by the government and its methods of tracking him violated his Fourth Amendment Rights.[20] He alleged that a Stingray was used without a warrant to track the Aircard, and argued that all evidence gathered from it must be suppressed from the record to comport with his constitutional rights.[21] He had sought extensive discovery from the government regarding the technology and methods used in tracking him, but the government opposed disclosure of the additional information sought by him by arguing that the information is protected by a qualified law enforcement privilege under Roviaro v. United States.[22] Rigmaiden contended that disclosure of this additional information is necessary if he is to litigate his Fourth Amendment arguments effectively.[23]

            While government disclosure of exculpatory evidence is required by law, historically, the United States has not provided defendants with the right to unfettered discovery in criminal cases.[24] However, Congress has created limited additional discovery rights through Federal Rule of Criminal Procedure 16.[25] Under this rule, the government has an obligation to disclose a document or object “if the item is within the government's possession, custody, or control and ... the item is material to preparing the defense.”[26] While Rigmaiden demonstrated his entitlement to discovery under Rule 16, the court cited Rovario, where the Supreme Court held that discovery may still be withheld when the government is entitled to a law enforcement privilege.[27] This is to be evaluated on a case by case basis, “balancing the public interest and protecting the flow of information against the individual's right to prepare his defense.”[28]

The court ultimately decided Rigmaiden had not shown that he had a legitimate expectation of privacy in his apartment, laptop, or Aircard and that he had not shown that his Fourth Amendment rights were violated because the Rovario exception applied here and law enforcement was entitled to a privilege to withhold this information.[29] Rigmaiden’s motion to suppress was accordingly denied.[30]

            The government now concedes that the use of the Stingray was a “search” under the Fourth Amendment, but it claims that it had a proper warrant comporting with the Constitution.[31]

However, the order it received by the court had only directed “Verizon to provide the government with information and assistance, but nowhere authorizes the government to search or seize anything.”[32] The government’s application for the warrant also made no mention of a Stingray or of any IMSI catcher.[33] While the judge signed off on this order, the government did not provide adequate information explaining what they were really planning on doing.[34] It was also later revealed that not only did the Stingray find Rigmaiden, but it collected records of every innocent cell phone user nearby.[35] The government claims to have had a “warrant” to find Rigmaiden, but it never had a warrant to obtain this information from these bystanders, effectively violating their Fourth Amendment rights.

The Government’s Improper Use of Stingrays: A “Legal Gray Zone”

The use of Stingrays by law enforcement agencies is considered to be a legal gray zone, especially because interference with communications signals is prohibited under the federal Communications Act.[36] As exhibited by Rigmaiden, judges are oftentimes left in the dark about the full extent of Stingray capabilities, and judges across the nation are potentially authorizing the use of the technology without fully understanding what it does.

The Electronic Frontier Foundation has referred to Stingrays as “the biggest technological threat to cell phone privacy” because of their widespread use by police departments and federal agencies across the United States.[37] Various federal agencies are known to use cell site simulators. These include the Federal Bureau of Investigation; the Drug Enforcement Administration; the U.S. Secret Service; Immigration and Customs Enforcement U.S. Marshals Service; the Bureau of Alcohol, Tobacco, Firearms and Explosives; the Internal Revenue Service, the U.S. Army, the U.S. Navy, the U.S. Marine Corps, the U.S. National Guard, U.S. Special Operations Command, the National Security Agency, and Customs and Border Protections.[38]

The Freedom of Information Act is a federal law that requires upon request the full or partial disclosure of previously unreleased information and documents that are under control of the United States government.[39] However, federal agencies are not under obligation to disclose such information if it falls under one of nine exemptions that protect interests such as national security, law enforcement, and personal privacy.[40] As such, federal and local police maintain a strict code of silence when it comes to the extent to which they utilize Stingrays.[41] In fact, a leaked document revealed that police agencies have been ordered to report any person who has filed a request under the Freedom of Information Act about Stingrays to the FBI.[42]

Another leaked document revealed that the FBI has requested local police departments to not only disclose any information about the devices, but also dismiss any cases that call into question the use of Stingrays.[43] The leaked FBI agreement stated in plain language that local law enforcement agencies are to stay quiet about the devices, even in court and during public hearings.[44] Even more egregious, the ACLU uncovered and published email exchanges between police departments in Sarasota Florida, and North Port, Florida that demonstrated that the local law enforcement agencies had concealed the use of Stingrays in court documents.[45] The emails revealed that the two departments had borrowed the cell phone trackers from the US Marshals Service, and it was under the direction of the US Marshals Service that they hid the use of the devices from defendants and judges in court.[46]

Another Justice Department document obtained by the ACLU of Northern California showed that when requesting permission to use Stingrays from federal magistrate judges, federal investigators routinely hide the fact that they are already regularly using them.[47] Also according to the ACLU, federal agencies additionally withhold information from judges about the full scope of the device’s capabilities.[48] The ACLU has argued that by withholding this information from courts in their applications for electronic surveillance orders, federal agencies are essentially seeking to write their own search warrants.[49]

            In the summer of 2020, the nation began to see a spike in protests across the country as people marched in support of the Black Lives Matter movements and against police brutality.[50] Throughout these protests, activists spotted recurring mysterious helicopters and planes flying overhead.[51] In May 2020, a press release from the Justice Department revealed that the U.S. Marshals Service and the Drug Enforcement Agency were asked by the Justice Department to provide throughout the protests to law enforcement.[52] The type of support requested was unspecified, but a memo from the acting administrator of the DEA that was obtained by Buzzfeed News revealed that the DEA had sought special authority from the Justice Department to “conduct covert surveillance” and collect intelligence on people participating in protests over the police killing of George Floyd.[53] While the memo did not specify the surveillance, both the Marshals and the DEA possess airplanes outfitted with Stingrays that could have potentially collected data and communications in bulk while flying over the protests.[54]

Steps Must Be Taken To Ensure that Governmental Agencies Do Not Continue Violating Our Fourth Amendment Rights Through Stingrays.

Beyond Rigmaiden, there is a trend of law enforcement inadequately explaining Stingrays to judges.[55] The government is using these devices to conduct broad searches to locate suspects, amounting to “general warrants.”[56] A stingray can potentially be used to scan an entire neighborhood, collecting the data of innocent people around the vicinity of the suspected individual, looking for a particular signal without any judicial approval.[57] This is the exact type of general fishing expedition search that the Fourth Amendment was written to prevent. The Supreme Court has said that a warrant requires probable cause for everything that is searched and should detail the scope of the search to ensure “nothing is left to the discretion of the officer executing the warrant.”[58] If courts continue to be uniformed by the government and accordingly continue to approve the unregulated use of Stingrays, the government is essentially being given a free pass to enter into our homes via a cellular signal at the discretion of law enforcement at will and without supervision. Through the use of Stingrays, the government is utilizing modern technology to undo centuries of Constitutional law precedent to conduct searches they would otherwise be prevented from physically doing.

In 2021, Senators Ron Wyden and Steve Daines introduced the Cell-Site Simulator Warrant Act, aimed at amending Title 18, United States Code, to regulate the use of cell-site simulators by establishing a probable cause warrant requirement for federal, state, and local law enforcement agencies.[59] The bill has been read twice and referred to the Committee on the Judiciary, but no further action has yet been taken.[60] It’s worth noting that the only penalty proposed in this act for entities that do not adhere to proper warrant procedure prior to the use of Stingrays is a fine.[61] While this bill is a step in the right direction, there is much more that needs to be done to ensure that governmental agencies do not have unrestricted freedoms to use Stingrays to side step warrant requirements and violate our Fourth Amendment rights. Politicians lawmakers must clearly define this vague and gray legal area to ensure that law enforcement agencies do not continue freely using Stingrays in this unjustifiable manner.

[1] Matthew Brage, et al., RCMP Reveals Use of Secretive Cellphone Surveillance Technology for the First Time, CBC (Apr. 5, 2017), https://www.cbc.ca/news/science/rcmp-surveillance-imsi-catcher-mdi-stingray-cellphone-1.4056750.

[2] Stingray Tracking Devices: Who’s Got Them?, ACLU (Nov. 2018), https://www.aclu.org/issues/privacy-technology/surveillance-technologies/stingray-tracking-devices-whos-got-them.

[3] Id.

[4] U.S. Const. amend. IV.

[5] Id.

[6] Brage, supra note 1.

[7] Benjamin Van Severen, Stingray Devices, Van Severen Law Office (Jul. 26, 2016), https://milwaukee-criminal-lawyer.com/stingray-devices/.

[8] Id.

[9] Id.

[10] Id.

[11] Cale Guthrie Weissman, How an Obsessive Recluse Blew the Lid Off the Secret Technology Authorities Use to Spy on People’s Cellphones, Business Insider (Jun. 19 2015), https://www.businessinsider.com/how-daniel-rigmaiden-discovered-stingray-spying-technology-2015-6.

[12]  Hanni Fakhoury & Trevor Timm, Stingrays: The Biggest Technological Threat to Cell Phone Privacy You Don't Know About, EFF (Oct. 22, 2012), https://www.eff.org/deeplinks/2012/10/stingrays-biggest-unknown-technological-threat-cell-phone-privacy. 

[13] Id.

[14] United States v. Rigmaiden, 844 F. Supp. 2d 982, 987 (D. Ariz. 2012).

[15] Id.

[16] Weissman, supra note 11.

[17] Id.

[18] Id.

[19] Id.

[20] United States v. Rigmaiden, 844 F. Supp. 2d at 987.

[21] Id.

[22] Id.

[23] Id.

[24] Id. at 988.

[25] Fed. R. Crim. P. 16.

[26] Fed. R. Crim. P. 16(a)(1)(E)(i).

[27] United States v. Rigmaiden, 844 F. Supp. 2d at 988.

[28] Roviaro v. United States, 353 U.S. 53, 77 (1957).

[29] U.S. v. Rigmaiden (Stingray) - Order Denying Motion to Suppress, ACLU, https://www.aclu.org/legal-document/us-v-rigmaiden-stingray-order-denying-motion-suppress.

[30] Id.

[31] Weissman, supra note 11.

[32] Id.

[33] Id.

[34] Id.

[35] Id.

[36] 47 U.S.C. § 333 (2013).

[37] Fakhoury, supra note 12.

[38] Brage, supra note 1.

[39] What is FOIA?, FOIA, https://www.foia.gov/about.html.

[40] Id.

[41] Kim Zetter, Florida Cops’ Secret Weapon: Warrantless Cellphone Tracking, Wired (Mar. 3, 2014), https://www.wired.com/2014/03/stingray/.

[42] Harris Government Communications Systems Terms and Conditions of Lease for Domestic Wireless Equipment, Software, and Services, Internet Archive, https://web.archive.org/web/20160315041050/https://s3.amazonaws.com/s3.documentcloud.org/documents/1657972/bca-cellular-exploitation-equipment.pdf.

[43] Scott R. Patronik, RE: Acquisition of Wireless Collection Equipment/Technology and Non-Disclosure Obligations, Internet Archive, https://web.archive.org/web/20160315040802/https://s3.amazonaws.com/s3.documentcloud.org/documents/1727748/non-disclosure-agreement.pdf.

[44] Id.

[45] ACLU-Florida-Stingray-Police-Emails, Internet Archive, https://web.archive.org/web/20160307194811/http://cdn.arstechnica.net/wp-content/uploads/2014/06/ACLU-Florida-Stingray-Police-Emails.pdf.

[46] Id.

[47] U.S. v. Rigmaiden (Stingray) - Declaration Submitting DOJ Emails, ACLU, https://web.archive.org/web/20160301041712/https://www.aclu.org/legal-document/us-v-rigmaiden-stingray-declaration-submitting-doj-emails?redirect=technology-and-liberty/us-v-rigmaiden-stingray-declaration-submitting-doj-emails.

[48] Linda Lye, DOJ Emails Show Feds Were Less Than “Explicit” With Judges on Cell Phone Tracking Tool, ACLU (Mar. 27, 2013), https://web.archive.org/web/20160226090832/https://www.aclu.org/blog/doj-emails-show-feds-were-less-explicit-judges-cell-phone-tracking-tool?redirect=blog/national-security-technology-and-liberty/doj-emails-show-feds-were-less-explicit-judges-cell.

[49] Linda Lye, DOJ Emails Show Feds Were Less Than “Explicit” With Judges on Cell Phone Tracking Tool, ACLU (Mar. 27, 2013), https://web.archive.org/web/20160226090832/https://www.aclu.org/blog/doj-emails-show-feds-were-less-explicit-judges-cell-phone-tracking-tool?redirect=blog/national-security-technology-and-liberty/doj-emails-show-feds-were-less-explicit-judges-cell.

[50] Kim Zetter, How Cops Can Secretly Track Your Phone, The Intercept (Jul. 31, 2020)

[51] Id.

[52] Id.

[53] LEOPOLD DEA Memo George Floyd Protests Surveillance, https://s3.documentcloud.org/documents/6935297/LEOPOLD-DEA-Memo-George-Floyd-Protests.pdf.

[54] Zetter, supra note 50.

[55] Weissman, supra note 11.

[56] Id.

[57] Id.

[58] Marron v. United States, 275 U.S. 192, 196 (1927).

[59] Jake Laperruque, Issue Brief: The Cell-Site Simulator Warrant Act, POGO (Nov. 22, 2021), https://www.pogo.org/resource/2021/11/issue-brief-the-cell-site-simulator-warrant-act.

[60] Cell-Site Simulator Warrant Act of 2021, TrackBill, https://trackbill.com/bill/us-congress-senate-bill-2122-cell-site-simulator-warrant-act-of-2021/2135219/.

[61] Cell Site Simulator Warrant Act of 2021 - One Pager, Wyden, https://www.wyden.senate.gov/imo/media/doc/Cell%20Site%20Simulator%20Warrant%20Act%20of%202021%20One%20Pager.pdf.