The technology is about the size of a laptop and used by law enforcement in criminal investigations.
Florida's ACLU says Stingrays – also known as Amberjacks and Triggerfish – do what their name sounds like: Fish for information, including in and outgoing phone numbers and texts.
"It's an electronic game of Marco Polo. It is a fake cell phone tower," said Vice President Florida ACLU Michael Barfield.
The data collected can locate an cellphone user, Barfield said. It can also tell police where the user has been and where he or she is going, along with other information.
Florida's ACLU filed a lawsuit Tuesday against the City of Sarasota after its public records requests were shut down by the Sarasota Police Department.
Barfield says the ACLU sees Stingrays as a privacy invasion.
"When the government collects this information, it doesn't just collect it on someone who's accused of or suspected of criminal activity. It's everyone within a one-mile range of that person. So all of your information is being stored and archived by the government," he said.
Florida's ACLU wants to know how many times the devices have been used, under what circumstances and where the information is stored.
Sarasota's deputy chief of police gave ABC Action News a quick statement on camera but wouldn't answer any questions.
"This is a civil matter. We disagree with the information that has been presented by the ACLU and we are working with our legal counsel in responding to this particular case," said Sarasota Police Deputy Chief Stephen Moyer.