On a day this past June, researchers were able to track a cell phone as it went from a residential address in Alabama to Tallahassee, Florida, where it remained for about two hours before going to another house in Mississippi.
The address in Tallahassee was an abortion clinic that explicitly advertises its services to out-of-state visitors.
Earlier this year, start-up company Atlas Privacy got access to a mobile phone-tracking tool used by law enforcement and U.S. government agencies across the country. The tracking tool, sold by Virginia-based company Babel Street, pulls commercially available data that phones beam out through apps. Atlas researchers were looking for privacy and security vulnerabilities in the data for sale.