I forgot about this, but at the same time that doesn't imply it's legal for a government agency to just give it away. There are obviously industries that gather up all your personal information from address and DoB to SSN but that doesn't mean a government agency can just give it out to a random nobody.
The difference in rational is pretty simple:
A plate identifies a vehicle. A vehicle is not a person. Govt can't give out personally identifiable information.
A vehicle’s owner is public information in the US. Credit Karma knows the vehicles I own based on DMV records, and recommends me insurance accordingly.
And they know that because your PII (name, address, social) is mapped to a profile, and that profile is also mapped to license plates and Vins. So you can use one to look up the other info in either direction.
(random example: https://www.syracuse.com/news/index.ssf/2015/01/private_comp... )