Soon the government of California will be able to modify the license plates on vehicles, notifying if they are expired, uninsured or have other types of warnings police should be aware of, all of this possible by electronic license plates.
The technology is like that used in some e-readers such as Amazon's Kindle or the Nook by Barnes & Noble, and it is expected that governor Jerry Brown will approve a new pilot program for the use of electronic licenses on motor vehicles, where 0.5% of registered vehicles in the state will get this new technology and see how fast the program can extend. It is not contemplated on being mandatory to the general public just yet.
There are concerns regarding privacy with the law, given that it will allow the government of California control over what is projected on the license plates, as warnings that the driver doesn't have insurance, has expired or suspended license plates. There can even be "Amber Alerts" published in case o kidnapped children or if it is a vehicle that has been reported stolen. But the law is very specific on what personal information the government can and cannot have, and is limited to "data necessary to project evidence of compliance with the registry, the DMV will not receive or keep information as far as travels, locations or use of the vehicle, generated during the pilot program."
Here you can see several examples of the alerts that can be displayed on the license plates and how they will look through the website of one of the authorized providers, Compliance Innovations.
Until now there hasn't been much opposition to the initiative, but some controversy is expected, given that it is basically technology that will allow the government to instantly control the information your vehicle displays.