> It's not unheard of for an officer themselves to be the stalker

This was one of the motivations for passage of the Driver's Privacy Protection Act of 1994. Nowadays, officers need a legitimate reason to run a plate - unless the patrol car is fitted with automatic cameras[1] that look up every plate of every car they drive past.

> The Virginia state police used license plate readers to track people’s attendance at political events; > The New York Police Department used license plate readers to keep track of who visited certain places of worship, and how often;

> Despite all this surveillance, ALPR technology has been repeatedly shown to be unreliable; like other police technologies, ALPRs can and do make mistakes.[2]

Generally, court decisions have held that you have zero expectation of privacy when you are in public spaces. Current license plate standards[3] aim for plates that are not cluttered and are easily read by the human eyeball, despite being wrapped with license plate frames (which usually make the state hard/impossible to read which is the most common failure mode for ANLR[4]). If the reflectivity material (traditionally called "ScotchLite"[5]) is worn out (or defaced), most states require the plate to be replaced.

Notes:

0 - https://en.wikipedia.org/wiki/Driver%27s_Privacy_Protection_... Prior to passage, a slang term for running/looking up the plate/registration of a car with a pretty woman driver was "running a date".

1 - https://sls.eff.org/technologies/automated-license-plate-rea...

2 - https://www.aclum.org/publications/what-you-need-know-about-...

3 - https://www.aamva.org/getmedia/646bcc8a-219b-47d8-b5cd-72624...

4 - https://www.aamva.org/getmedia/0063bf88-cb44-4ab9-90b6-200c8...

5 - https://www.3m.com/3M/en_US/scotchlite-reflective-material-u...

Disclaimers:

I used to work for my state's motor vehicle department and had database/developer access to driving licenses and motor vehicle registration records.

I graduated from a police academy when I was a youngster.*