Several justice advocacy groups pushed back against the Baltimore Police Department’s (BPD) controversial use of “stingray” cell phone tracking technology via a complaint filed with the Federal Communications Commission (FCC) today (August 16).

“The public is relying on the Commission to carry out its statutory obligation to do so, to fulfill its public commitment to do so, and to put an end to widespread network interference caused by rampant unlicensed transmissions made by BPD and other departments around the country,” Color of ChangeThe Center for Media Justice and The New America Foundation’s Open Technology Institite write in the joint complaint, which was provided to Colorlines.

The Baltimore Sun says that stingrays—or cell site simulators (CS simulators)—involve signals that imitate a cell phone tower so that nearby phones will automatically join the fake network. Police can then track individual cell phones’ locations. The BPD faced criticism last year after officials admitted to using them in court. The complaint argues that stingrays infringe upon free speech rights (especially for those protesting against Baltimore police) and disrupt cellular networks used to make emergency calls:

This interference with calls extends to emergency calls. In this way, these devices disrupt the cellular telephone network and emergency services. Like other law enforcement surveillance equipment, CS simulators also chill speech, including the speech of protestors focusing scrutiny on BPD

Worse, the harms that stem from BPD’s use of CS simulator equipment fall disproportionately on Baltimore’s Black residents. BPD is most aggressive in Black neighborhoods; indeed, according to a recently released report from the Department of Justice, BPD clearly exercises its enforcement authority in a way that is statistically heavily biased against African Americans. Where BPD focuses its policing power, it also focuses its surveillance technology—including CS simulator equipment—and residents in targeted neighborhoods therefore suffer disproportionate harms.

The Department of Justice report referenced is most likely this one from last week.

The complaint suggests that the BPD uses this technology at a higher rate than other cities for which such information is available, in part because it ”does not limit its use of CS simulators to exceptional cases.” It also states that the BPD violates federal law because it lacks a proper license to use stingrays—a violation falling under the FCC’s regulatory purview. As of press time, neither the FCC nor the BPD had officially responded to the complaint.

Today’s filing echoes criticism of the BPD and other police departments for using technology that closely monitors anti-police violence protest activity and furthers surveillance on heavily-policed communities of color.