Once the use of a surveillance technology is permitted for emergency purposes only, it is only a matter of time before it is used for purposes that fall well outside any rational definition of an emergency.

Take automatic license plate readers, or ALPRs, for instance. All across the country, these surveillance cameras capture time-stamped data for passing vehicles (e.g., license plate number, location, color, bumper stickers, items in the back seat), then transfer that information to a searchable nationwide database.