Government officials across the U.S. frequently promote the supposed, and often anecdotal, public safety benefits of automated license plate readers (ALPRs), but rarely do they examine how this very same technology poses risks to public safety that may outweigh the crimes they are attempting to...
The locations of the license plates. Yes, people's location history is sensitive, and can be used for a lot of harm.
As for storing the information, that's where all the benefit comes from. To be useful, they have to be able to query the database for, eg., kidnapper's car and track where they've been. Without that you don't even have a debate of risk vs reward. It's not downside outweighing upside. It's all downside.