An idea to address privacy problems with this: 1) Only have the information for licence plate codes of people who have opted in be stored in a way associated w

An idea to address privacy problems with this: 1) Only have the information for licence plate codes of people who have opted in be stored in a way associated with the specific licence plate code. 2) Have the system encourage opting in as part of setting up the system in one's own car. 3) Have an id which is used for all cars which have not opted in, so that cars which have not opted in have a collective rating. Possibly split this up by general location, and maybe time of day. 4) Because most of the cars in a given area are there often (or, at least something similar to this is true) , it may be worthwhile for, for the cars that do not opt in, to still record behavior of those cars, but to not send it to a central location, only keeping it within one's own car. Cars which have not been seen in a long time can be automatically removed from the local storage. This should not significantly harm privacy, because it is basically the same as remembering that you saw that car before and that it tended to be driven poorly. 5) Possibly (this might always be pointless/counterproductive. I'm not sure.) , in some cases only store a hash of the license plate codes, instead of the license plate code itself? A) I think this variation should be sufficient to protect privacy, because it only does widespread collection about identifiable individuals if they they consent to it. The information it collects about individuals that did not specifically (and presumably intentionally) express consent is only collected in aggregate about individuals in a geographic region, which does not personally identify anyone, or only collected by individuals and not shared, which is not much more of a privacy violation than an individual with excellent memory looking around. B) So, while this variation might be less effective, I think it should be sufficient to protect privacy.