[onewaystreet]

This is already being done by companies and police forces using their own vehicles. It's more efficient than outsourcing it through an app because cameras mounted on the roof of a vehicle can scan license plates in 360 degrees.

[basseq]

This is very common with towing, repossession, or "recovery" companies, who can drive around with automated cameras looking for "hits": cars with repo orders. Companies (ex: Digital Recognition Network [DRN]) sell cameras, provide a database of "wanted" vehicles, and collect the incoming scans—which they also turn around and sell.

DRN "claims to collect plate scans of 40 percent of all US vehicles annually."

You don't need to crowdsource because there's already a critical mass of users willing to pay YOU for the privilege of collecting information.

Read More: http://www.betaboston.com/news/2014/03/05/a-vast-hidden-surv...