One aspect of this that isn't widely discussed is that license plate data collected is often shared or rented to auto financers and lenders by the company or municipality collecting the data. It allows them to keep tabs on subprime auto loan debtors (the numbers of which have been booming in the US the past few years).

Sources: http://www.npr.org/sections/alltechconsidered/2014/10/16/356...

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