"Does it really matter if big shops track you? How can you avoid it? I mean they can track what you buy via your credit/debit card, loyalty card. They could potentially track you via CCTV and face recognition software.
...
My concern would be if a government or foreign agency got hold of that data."
I'm not sure there's much difference between Tesco tracking you around it's shop in order to try and increase the amount you spend with them and government tracking you around the city centre in order to increase footfall, or whatever they choose to do with the new found details. Both these organisations probably have far more personal information about me either through legal obligation or my willingness to surrender it in exchange for "Free" services.
Any app on your phone which doesn't appear to have a stream of income (and some that do) are likely to be making their money by commoditising you. Facebook for instance stop you from accessing messages through a mobile browser in an attempt to force you to download their app so that they can then access your contacts, location and whatever else they can find on your phone.
Google probably has a better idea of where you are then your closest family members and I'm sure can remember better where I was this time last month than I can. The offer some very useful free services using this data such as their real time traffic updates, however they are only doing this so that you keep feeding them the information. I don't know where they draw the line but I'm sure if a government agency approached them with enough money they would be happy to share a lot of (possibly anonymous data). Or alternatively start offering more targeted advertising on those large tellies which are appearing next to more and more roads.
/EEN mode