Flock cameras capture license plates and vehicle details, creating a searchable record of where cars have been seen. USA TODAY Investigative Data Reporter Austin Fast explains how USA TODAY's analysis of 75 million searches uncovered troubling patterns, including officers repeatedly tracking the same vehicles, and why the findings are intensifying concerns about privacy, surveillance and oversight. Let us know what you think of this episode by sending an email to [email protected]. Episode transcript available here. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.