A network of little black cameras on tall metal posts has sprouted up across Texas, in big cities and along remote country roads.

The cameras, produced by Atlanta-based Flock Safety, use artificial intelligence to scan every vehicle that passes by, uploading the plate number, model, color and even bumper stickers to the country's largest vehicle surveillance database.

Law enforcement agencies that contract with the company - here and across the U.S. - can search the accumulated database with a few keystrokes and without a warrant.