system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Since the owls in the potterverse always seem to know where people are, why don't they use it as a way to track people down?
gpt
By making yourself and your location untraceable. Owl magic can get around that most of the time, but makes an untraceable charm makes it impossible for others to follow.  

At the same time, Sirius was aware that even making himself untraceable could still lead the Ministry to his rough location.  That's why he used different owls and had Harry address him as Padfoot.