The government violates the privacy rights of individuals on pretrial release when it continuously tracks, retains, and shares their location, EFF explained in a friend-of-the-court brief filed in the Ninth Circuit Court of Appeals.

In the case, Simon v. San Francisco, individuals on pretrial release are challenging the City and County of San Francisco’s electronic ankle monitoring program. The lower court ruled the program likely violates the California and federal constitutions. We—along with Professor Kate Weisburd and the Cato Institute—urge the Ninth Circuit to do the same.

Under the program, the San Francisco County Sheriff collects and indefinitely retains geolocation data from people on pretrial release and turns it over to other law enforcement entities without suspicion or a warrant. The Sheriff shares both comprehensive geolocation data collected from individuals and the results of invasive reverse location searches of all program participants’ location data to determine whether an individual on pretrial release was near a specified location at a specified time.

Electronic monitoring transforms individuals’ homes, workplaces, and neighborhoods into digital prisons, in which devices physically attached to people follow their every movement. All location data can reveal sensitive, private information about individuals, such as whether they were at an office, union hall, or house of worship. This is especially true for the GPS data at issue in Simon, given its high degree of accuracy and precision. Both federal and state courts recognize that location data is sensitive, revealing information in which one has a reasonable expectation of privacy. And, as EFF’s brief explains, the Simon plaintiffs do not relinquish this reasonable expectation of privacy in their location information merely because they are on pretrial release—to the contrary, their privacy interests remain substantial.

Moreover, as EFF explains in its brief, this electronic monitoring is not only invasive, but ineffective and (contrary to its portrayal as a detention alternative) an expansion of government surveillance. Studies have not found significant relationships between electronic monitoring of individuals on pretrial release and their court appearance rates or  likelihood of arrest. Nor do studies show that law enforcement is employing electronic monitoring with individuals they would otherwise put in jail. To the contrary, studies indicate that law enforcement is using electronic monitoring to surveil and constrain the liberty of those who wouldn’t otherwise be detained.

We hope the Ninth Circuit affirms the trial court and recognizes the rights of individuals on pretrial release against invasive electronic monitoring.