top of page

Cell Site Simulator Technology Violating Fourth Amendment Rights

In the age of modern technology, the balance between individuals’ privacy rights and national security have been heavily weighed. Advances in technology have enabled government agencies to obtain cellular information without appropriate judicial review and without the individual’s knowledge. Due to public outcry and complaints made by the American Civil Liberties Union, the Federal Government felt that appropriate action should be taken to minimize the use of this rare technology and has restricted the use of cell-site simulator technology without a warrant; however, state and local governments have not been instructed to do so and many have failed to address the issue at all. 1

The Fourth Amendment protects persons’ personal privacy from government intrusion.2 When intrusion leads to the obtainment of intimate knowledge, it will be deemed unreasonable unless the need for the public interest is outweighed by the privacy interest of the individual.3 For a search to be reasonable, officers generally will need to acquire a search warrant signed by a magistrate.4 If information is obtained without a search warrant and without an exception to the search warrant clause, it will be deemed inadmissible at trial.5

The use of technology, not acquirable by an ordinary person, dates back to the Supreme Court’s decision, Kyllo v. United States.6 The Supreme Court held that the obtainment of information through sense-enhancing technology into the interior of the home, that could not have been obtained without a physical intrusion, is a search.7 The Supreme Court has also determined that the monitoring of a beeper device in a private residence, not in a location open to visual surveillance, is a violation of the Fourth Amendment.8

More recently, with the storage capacity of modern cellular devices, the Supreme Court has instructed that the Government must obtain a search warrant before conducting a search of the content.9 This is because of the vast amount of intimate information such as emails, medical information, photographs and credit card information.10 The protection is placed on what a person preserves as private and in the modern era, the contents of a cellphone will be preserved as private to most individuals.

It has recently come to light that government agencies, local and federal, have been using cell-site simulator technology to obtain physical locations of suspects. A cell-site simulator, known as Stingray, acts as a substitute cell tower and awaits signals from particular cellular phones.11 Based on the strength of the signal, a general location can be determined.12 Once multiple signals and locations have been obtained, a precise location is then determined.13 The location is so precise that it can pinpoint the cellular phone to a particular room in a large building. Based on precedent, Courts are likely to hold that the use of Stingray is a search and inadmissible without obtaining a warrant. The ability to obtain tracking information from the device is in violation of the decision in Riley v. California, where the Court held that a cellular phone may  not be accessed and searched without first obtaining a warrant or consent.14 This technology is also rare technology that is not available to the general public and would physically intrude into an individual’s home.15

The Department of Justice has recently drafted and adopted a policy instructing government agencies to obtain appropriate approval before utilizing cell site simulators.16 This was in light of claims being made by organizations like the American Civil Liberties Union that the government was failing to inform the courts that they have access to this information and instead reported using criminal informants to obtain the information.17 While this was determined to be used more often local police departments, this technology allowed the ability for the Government to violate individual’s privacy rights.

After the Department of Justice drafted a policy requiring investigators to obtain warrants before using cell site simulators, state and local departments have not been forced to do the same. There are even loopholes to this policy. It merely applies to criminal investigations NOT national security or border cases. This means, that the Government has the ability to use Stingray when “monitoring” the border for national security. Has the Government failed to protect its citizens again? After the excessive collection of citizen’s information found under the United States Patriot Act, shouldn’t the Government protect individuals’ privacy rights at a higher level? Also, does this new policy prohibit the use of Stingray on suspected terrorists without a warrant? To many questions are still left unanswered after the drafting of this policy that needs to be answered.

  1. Neema Singh Guliana, ACLU, The Four Biggest Problems With DHS’s New Stingray Policy, Oct. 22, 2015, available at

  2. U.S. Const. Amend. IV.

  3. Kyllo v. United States, 533 U.S. 27, 36 (2001).

  4. U.S. Const. Amend. IV.

  5. Id.

  6. Kyllo, 533 U.S. 27.

  7. Id. at 40.

  8. United States v. Karo, 710 F.2d 1433, 1439 (1983).

  9. Riley v. California 134 S. Ct. 2473, 2494 (2014).

  10. Id.

  11. Department of Justice, Department of Justice Policy Guidance: Use of Cell-Site Simulator Technology, Sept 3, 2015, available at

  12. Id.

  13. Id.

  14. Riley, 134 S. Ct. 2473, 2494.

  15. Kyllo, 533 U.S. 27.

  16. Department of Justice, Department of Justice Policy Guidance: Use of Cell-Site Simulator Technology, Sept 3, 2015, available at

  17. Jeremy Schahill & Margot Williams, The Intercept, Stingrays: A Secret Catalogue of Government Gear for Spying on Your Cell Phone, Dec. 17, 2015,  available at


bottom of page