June 11, 2020

Could Contact Tracing Technology Violate the Fourth Amendment?

Patrick McKnight

Contact tracing has been used by health officials to understand and combat the spread of contagious diseases for over 100 years. For most of this time period contact tracing involved low-tech, on the ground interviews and investigations. Contact tracing has been used to combat the spread of diseases ranging from typhoid in the early 20th century to AIDS in the 1980’s and Ebola in the 2010’s.

Today, traditional contract tracing models are using technology to help fight the spread of COVID-19. For example, according to California’s COVID-19 contact tracing homepage, if an individual is exposed to COVID-19 they could get a call, text or email from their local public health department to let them know someone they have been in contact with has tested positive. Information about who may have exposed them is confidential and will not be shared. California, New York, and other states have announced plans to employ over 10,000 contact tracers each.

Given the sheer scale of the COVID-19 pandemic in America, reliance on the traditional model of voluntary interviews may be impracticable. Other contact tracing proposals are more ambitious in their use of technology to help “flatten the curve” of the disease. Technology Assisted Contact Tracing (“TACT”) is already being used in several countries including Singapore and Australia.

Most TACT proposals involving mobile phone applications depend on some form of “proximity tracking” using either GPS or Bluetooth technology. As a result, privacy advocates are raising concerns about the potential for increased surveillance over American citizens. Critics are particularly concerned about the use of GPS information and the use of centralized databases. North Dakota, Alabama, and South Carolina have already announced they will be using mobile phone applications using Bluetooth technology to trace potential contacts.

Many employers in the private sector are also evaluating the potential uses of TACT for the workplace.

CDC Guidance

The Centers for Disease Control and Prevention (“CDC”) released interim guidance on preliminary evaluation criteria for digital contact tracing tools. The CDC list of minimum capabilities includes consent, access, and data encryption. The CDC lists providing individuals the ability to delete their own data as a preference, but not a minimum capability, of digital contact tracing tools.

Competing COVID-19 privacy bills have been introduced in Congress. Both proposals contain an opt-in requirement for the collection and use of an individual’s COVID-19-related data before it can be used by businesses.

Fourth Amendment Concerns

TACT proposals vary widely in both their technical specifications and privacy implications. Critics worry many of these proposals, if implemented by governments on a mandatory basis, could violate an individual’s reasonable expectation of privacy under the Fourth Amendment as under the Katz decision.

For many years, the government relied on the third-party doctrine to utilize information volunteered to third-parties, including mobile phone carriers and technology companies. However, this analysis has become more complicated in recent years after the traditional approach to the third-party doctrine was limited by the Supreme Court’s Carpenter decision.

In a recent blog post, the American Civil Liberties Union outlined several concerns with Bluetooth-enabled TACT programs and proposals for “immunity passports” which could limit an individual’s ability to travel freely.

“We don’t yet know if any of these technologies will work, but we do know that we currently lack many of the protections needed to guard against abuse or overreach,” ACLU Senior Legislative Counsel Neema Singh Guliani explained. “If we as a country decide to go down the path of tech-assisted contact tracing, our lawmakers must first enact robust safeguards to prevent these tools from exacerbating existing disparities and violating our civil rights and liberties.”

Unconstrained by privacy laws, the Chinese government has expanded its domestic surveillance system in response to the COVID-19 pandemic. China has introduced robust contact tracing technology including mandatory mobile phone applications. The app functions like an immunity passport and determines where an individual may travel based on their past location data. Some reports indicate these programs have helped reduced the spread of COVID-19 in the world’s most populated country. Even prior to COVID-19, China has used facial recognition technology and biometric identification to monitor the movement of individuals.



The COVID-19 pandemic presents a new frontier in the ongoing attempt to balance technology and privacy. TACT presents exciting new opportunities to isolate potential exposures to the virus.

It is important to note TACT proposals vary widely in many significant technical details. Each proposal should be evaluated carefully on a case by cases basis, with appropriate consideration given to the potential for unintended long-term consequences.


Patrick McKnight

Klehr Harrison Harvey Branzburg LLP