Folks, let's walk this back a bit, shall we? We're getting into the Twilight Zone here.
The use of the term "very interesting information" was perhaps ill-advised. I said this before but it bears repeating: LEOs have access to information that is public record. And I can assure you that there is precious little about it that is in any way interesting.
They don't have access to credit reports, or medical records, or any other personal, private information. Certainly everyone here is savvy enough to know that such a suggestion is absurd.
IF a LEO is conducting an investigation in which he needs to see anything along those lines he must convince a judge to give him a search warrant.
No matter how much people opine here about 4th Amendment rights it is a well-established legal fact that you have no privacy rights where your license plate is concerned. It is a public record and it is publicly displayed for a reason. When a LEO runs your license plate your privacy has not been invaded because it is not a private subject. Also, that LEO has not harmed you or your rights in the slightest degree. You have privacy rights in some subjects and not in others. If you're standing on a public street and another citizen takes your picture, your privacy has not been violated.
Liberty, I haven't disagreed with much that you have commented on this topic. I have tried to be open and point out that there is a difference in the viewpoints of the LEO and the majority of civilians on this topic.
I guess the synopsis for me is that yes this it is legal for an LEO to run my info and pry (which is what they are doing) into my background. How ever it is not mandated that it be done. Leo's has a choice and I would hope that individual LEO's might make an ethical decision based on how they would feel if another government agency decided it was legal to invade their personal information just because they wanted to.