When did you last see your girlfriend?
The principle of mobile phones, and how you are able to connect two mobiles to speak with the number you dialled; is at the same time fantastically complex and remarkably easy. The ‘Cell’ principle, whereby every phone within radio contact of the aerial base set automatically gets registered with that base as being active. If you dial another mobile number, an extremely fast and robust computer system locates where that particular phone is located, switches through, and lo and behold, you are speaking to your colleague, or mate, or indeed your father. Early attempts at mobile phone use fell apart when it was found that the numbers of ‘cell bases’ were not sufficient to allow contact with people who moved in and out of the ‘cell’ coverage.
As the systems grew more popular, and more investment was pured in, mobile coverage improved, and suddenly I could call my mate in another car just ahead of me on the A2 coming into London(on hands-free phones, of course). So your phone, and of course you, are already logged in as to your whereabouts from the very beginning of mobile phone use.
I repeat, your position, down to the certain area of the ‘cells’ which you were registered to, is already known and logged.