The leak of highly classified documents by National Security Agency Edward Snowden prompted tighter restrictions on key technology advances, said Georgia Bureau of Investigation Director Vernon Keenan, speaking at the International Association of Chiefs of Police conference.

 

The disclosures, including about monitoring of U.S. phone records, threaten to erode existing authority to use high-tech equipment, he said.

 

"The scrutiny that the NSA has come under filters down to us," Keenan said at the annual gathering that draws top law enforcement from the United States and elsewhere with workshops, product exhibits and conferences.

 

He said guidelines for collecting data varied widely from state to state. License plate data is retained for 48 hours to five years, for example, depending on local law, he said.

 

For many new technologies, there is no clear legal standard to govern their use, he said.

 

"If we are not very careful, law enforcement is going to lose the use of technology," he said.

 

New technology including advanced facial recognition software, mobile license plate readers and unmanned aircraft are reshaping U.S. law enforcement, officials said.

 

Such advances will be "both the benefactor and the curse of policing" and demand that law enforcement be thoughtful about their deployment, Philadelphia Police Chief Charles Ramsey said on Saturday at the start of the weeklong conference.

 

"Imagine instead of driving down the street scanning license tags, driving down the street checking the faces of individuals walking down the street," Ramsey said.

 

"We have to remind ourselves – just because we can do something doesn't mean we should do it."

The Philly police chief is right. Law enforcement is confronted with a citizenry that is waking up to the reality of the surveillance state, which includes local police department participation in federal monitoring programs like "Suspicious Activity Reporting," as well as the deployment of high-tech tools like license plate readers, surveillance cameras, and automated tracking technologies.

Ramsey warns that police shouldn't do things simply because they can — that they shouldn't take advantage of a legal climate in which technology has far surpassed legal protections. But that doesn't go nearly far enough.

Instead of asking police departments to police themselves, we need clear laws to govern how departments can use these new technologies. The Fourth Amendment provides critical guidelines, but courts, legislatures, and police departments have varying views on how exactly to apply those guidelines to new surveillance and identification technologies. 

We at the ACLU aren't confused, however. We believe the gold standard of American justice, the probable cause warrant, should broadly apply in the digital age. If the police want to track us, read our emails, or monitor our comings and goings using high-tech tools like drones, license plate readers, face recognition, or signals interception technologies, they should get a warrant. 'Just trust us' didn't work in the 20th century, and it most certainly doesn't work in the 21st. 

The warrant standard protects our privacy by ensuring that police cannot use broad subpoena powers to conduct fishing expeditions, or to monitor their ex-girlfriends. The warrant also protects public safety, by focusing limited law enforcement resources on people against whom the government has evidence to believe are engaged in crimes.

Law enforcement should join us, instead of fighting us, as we seek to advance privacy protections for everyone in the United States. After all, if they are only interested in spying on the 'bad guys', what do the police have to hide?