Actually in China they do track people and then round them up by forcing them to install apps on their phones (https://www.ibtimes.com/china-forces-muslims-inst

Actually in China they do track people and then round them up by forcing them to install apps on their phones (https://www.ibtimes.com/china-forces-muslims-install-anti-terrorist-surveillance-app-phones-2570495 https://www.ibtimes.com/china-forces-muslims-install-anti-te...) which is not that far from putting an RFID chip under their skin. If RFID chips were cheaper than install a phone app I’m sure they’d do that instead.