I think the US already has big private networks of number plate recognition cameras that sell feeds to cops, bounty hunters, advertisers, and traffic alert companies. It wouldn't be much of a hop.
I can't remember the name of the project, but at least NY is full of CCTVs that record and index everything (ie tracking the position of cars, pedestrians all with searchable characteristics ie colors, car models, biometrics etc).
But I haven't heard about "retail" data sales or any data sales/private sector services in general.