Data: Finding Flock; Map: Brad Jennings/Axios; Note: Counties shown in gray have no listed ALPR cameras.
About 140,000 automated license plate readers, including thousands of Flock cameras, are installed across the U.S., according to this publicly available data.
Why it matters: The cameras can help police find stolen cars and wanted people, but their ability to track all vehicles all the time has fueled a growing privacy backlash and calls for tighter oversight or removal.
By the numbers: Harris County, Texas, home to Houston and nearly 5 million people, has more than 4,000 cameras logged on the Finding Flock map, the most of any county.
The debate is intensifying as some communities reconsider or remove the cameras amid concerns about surveillance and instances of misuse.