From Tennessee to the District of Columbia, police are using mobile and stationary surveillance cameras to collect and store license plates of residents who have committed no crime—so that they can be found if they ever do.

In Tennessee, police utilize cameras mounted atop patrol cars that can capture thousands of license numbers each day. The information is then loaded into an ever-expanding database, which can help officers locate a vehicle in the event its owner is suspected of criminal behavior. The program is now expanding to include stationary cameras mounted next to busy roads.

“I’m sure that there’s going to be people out there that say this is an invasion of privacy,” Detective James Kemp of Gallatin County told The Tennessean. But “the possibilities are endless there for solving crimes. It’s just a multitude of information out there—to not tap into it to better protect your citizens, that’s ludicrous.”

In Washington D.C., local police make use of 250 cameras set up around the city that can capture license plates. Last year they claimed that the cameras led to an average of one arrest a day. DC reportedly has the highest concentration of cameras per square mile in the United States for spotting criminals on the move or just ordinary citizens going about their lives.

Jay Stanley, senior policy analyst for the American Civil Liberties Union’s technology and liberty program, expressed concern over D.C.’s “large database of innocent people’s comings and goings.” He told The Washington Post: “The government has no business collecting that kind of information on people without a warrant.”

Others predict that the technology will be declared constitutional because license plates are displayed in public, so there is no invasion of privacy.

-Noel Brinkerhoff

To Learn More:

License Plate Readers: A Useful Tool for Police Comes with Privacy Concerns (by Allison Klein and Josh White, Washington Post)