There are multiple data points that can be used and/or correlated to determine location, including IP address, if permissions are enabled, nearby Bluetooth devi

There are multiple data points that can be used and/or correlated to determine location, including IP address, if permissions are enabled, nearby Bluetooth devices, nearby WiFi MAC addresses, connected cell tower, and of course GPS. Also they don't even need to be installed on the journalist's device, but their child/spouse/coworker/close friends would also do.