[TelmoMenezes]

Then you're the sort of person who is not necessarily close to their phone. If banks are in fact doing this sort of thing, they surely take into account past behaviour to compute the probability that unexpected behaviour is related to credit card theft.

Maybe they don't even know that they are doing it. Maybe they just trained some neural network to attain certain levels of precision/recall. Maybe they feed the network with all the signals they can put their hands on. Things are not this simple anymore. Which also means that assuming phone tracking is a huge jump to conclusions, of course.