Erin Kelly

USA TODAY

A bipartisan group of House and Senate lawmakers introduced legislation Wednesday requiring police agencies to get a search warrant before they can deploy powerful cellphone surveillance technology known as "stingrays" that sweep up information about the movements of innocent Americans while tracking suspected criminals.

“Owning a smartphone or fitness tracker shouldn’t give the government a blank check to track your movements," said Sen. Ron Wyden, D-Ore., a member of the Senate Intelligence Committee who introduced the bill with Reps. Jason Chaffetz, R-Utah, and John Conyers, D-Mich. "Law enforcement should be able to use GPS data, but they need to get a warrant. This bill sets out clear rules to make sure our laws keep up with the times."

Stingrays are suitcase-sized devices that can pinpoint a cellphone’s location within a few yards by essentially masquerading as a cell tower. While they can help police track suspected criminals, the devices also intercept information from the cellphones of innocent people who just happen to be nearby. Dozens of police departments throughout the U.S. use the devices, often concealing that fact from suspects and their lawyers during court proceedings.

Courts have issued conflicting opinions about whether government agents need a warrant to track Americans through their cellphones and other GPS devices. The Supreme Court ruled unanimously in 2012 that police must obtain a warrant before attaching a GPS tracking device to a suspect's vehicle. However, the court did not say whether a warrant is required to track people through their cellphones, the OnStar systems in their vehicles, or other electronic devices such as fitness bracelets.

"Congress has an obligation to act quickly to protect Americans from violations of their privacy made possible by emerging technologies," said Chaffetz, chairman of the House Oversight and Government Affairs Committee. "As we welcome innovative technologies that help fight crime, we must be mindful of the potential for abuse."

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The legislation introduced Wednesday, called the Geolocation Privacy and Surveillance (GPS) Act, would require a warrant for all domestic law enforcement agencies to track the location and movements of individual Americans through GPS technology without their knowledge. It also aims to combat high-tech stalking by creating criminal penalties for secretly using an electronic device to track someone's movements.

"When individuals are tracked in this way, the government is able to generate a profile of a person’s public movements that includes details about a person’s familial, political, professional, religious, and other intimate associations," Conyers said.

The bill is supported by major privacy and civil liberties groups.

"In today’s world, most Americans use cellphones or other electronic devices that are capable of tracking their every move, including visits to a mosque, doctor’s office, domestic violence shelter, or political rally," said Neema Singh Guliani, legislative counsel at the American Civil Liberties Union. "This is information that the government should not be able to get without a warrant, yet law enforcement routinely fails to meet this standard. Congress should swiftly pass the GPS Act to protect this sensitive information."

FBI Director James Comey has said that law enforcement's use of stingrays is crucial to tracking and capturing criminals. The Justice Department said in 2015 that it changed its policy to require federal agents to obtain warrants before deploying the devices. However, many local and state police agencies continue to use stingrays without warrants.

"It's how we find killers, it's how we find kidnappers, it's how we find drug dealers, it's how we find missing children, it's how we find pedophiles," Comey said in 2014 in a rare public statement about the FBI's use of the surveillance technology. "It's work you want us to be able to do."