A guy driving from Washington state to Alabama kept passing black poles with solar panels on top, googled what they were, and ended up building a map of 125,000 police cameras that nobody had ever bothered to list. They're license plate readers. Every car that passes gets photographed and logged, whether or not anyone is looking for it. Flock Safety sells them to more than 6,000 agencies across 49 states. Billions of plate reads a month, kept 30 days by default. Will Freeman used a free map…