If they manage to read the license plates properly, they'd only record the plate, the date, and the camera ID, as Kara said. That would be about 38 bytes (12 for the plate, 16 for the timestamp, and 10 for the camera. I'm allowing for 10^10 camera;s here.) Saying there's a camera every mile, you'd meet 60 for every hour your drove (more or less), and even spending 24 hours behind the wheel a day would leave you with 60*24*38=54kb per day per car. that's easy to store. In reality, going for two hours a day is more likely, making 4,5kb. Even when there are 10 million cars (number out of thin air), you'd have 4,5*10.000=45000kb meaing 45 MB a day. 16GB a year. That means that I could store about 5 years of data on my own HD. And I'm sure that I've been pessmistic on some parts of that calculation.
To find out the movements of someone in the last 24 hours, this'd be sufficient:
SELECT * FROM `1984db` WHERE `licence`LIKE "AB-CD-55" AND `date `LIKE ` '11362%%%%%' ORDER BY `date`.
If you want to get someones movements for the last five years, just remove AND `date `LIKE ` '11362%%%%%' and there you are.
And then you'd have a record of every camera post where that car has been spotted. Not all that hard to plot that to a map either.... Do you really want it to be that easy for someone to track you?
