Readable, sure.  They provided a way to identify the owners of <i>specific</i> cars without stopping them.<p>But with the advent of digital photography, image recognition, and computerized databases, they do something very different.  They make it possible to track <i>everyone</i> passing through a place, and to correlate every sighting of <i>someone</i> to build up a profile of their life.<p>Sure, surveillance isn&#x27;t novel.  But a sufficient quantitative difference becomes a qualitative difference.  Bulk tracking of everyone in a city is something completely new, and there&#x27;s good reason to be uncomfortable with it.