If you had near continuous location information for a license plate it would be relatively simple to use it to narrow it down to a small group of people.

I’d imagine it would be relatively easy to figure out where someone works and/or lives and just go find them.

Correlating across multiple public databases might make things even easier.

But I don’t think this is the point of the argument. The point is that those in power can gain more benefit from the information than the general population.

Let’s say all votes in elections become public. That information is more useful to a powerful political party than to the public at large, or a small unfunded group. If you don’t want that information abused, the argument goes, you should make sure it’s kept private.