Shocking this took so long to appear in the wild...
Apparently, high school kids in suburban Maryland have been creating fake license plates and using them to send speeding tickets to people they don't like, including their teachers. See http://www.thenewspaper.com/news/26/2632.asp. This appears to be a manual exploit at this point -- they 'shop up the desired fake plate and then color laser print it on glossy paper. I think it will a relatively short time before a fully-weaponized fifty state exploit appears in the wild.