Even further back. There has not been a mobile phone system (AMPS, GSM, etc.) that did not have a way for the Gummint to listen in. And with the arrival of CDMA all phones now have GPS, which means they have location down to the meter, and with WIFI and Bluetooth and RFID/NFC plus devices that do not have a removable battery, there is nothing they don't know.
Even further back. There has not been a mobile phone system (AMPS, GSM, etc.) that did not have a way for the Gummint to listen in. And with the arrival of CDMA all phones now have GPS, which means they have location down to the meter, and with WIFI and Bluetooth and RFID/NFC plus devices that do not have a removable battery, there is nothing they don't know.