Yep, and the modern day thing seems to be buying or hacking the movememt data directly from the telco. For example if leaks are to be believed NSA has access to

Yep, and the modern day thing seems to be buying or hacking the movememt data directly from the telco. For example if leaks are to be believed NSA has access to around 70% of the movement data of GSM subscribers in Pakistan. That said, there has been a sigint sat parked close below Thurayas sat for ages.