The iPhone 5s tracks your movements for 4 days after the battery dies
For those of you who are concerned about privacy and big companies tracking you, the focus of those fears tend to be Google and Facebook, but it looks like you have to add Apple to the list as well. A new report is claiming that the iPhone 5s (and likely the new iPads that also feature the M7 coprocessor) can track your movements for up to 4 days after the device's battery dies.
This is anecdotal and hasn't been confirmed yet, but Reddit user Glarznak has interesting evidence. Apparently, Glarznak was on vacation in Europe and his iPhone battery died. His charging cable had broken, so he decided to just go without his phone for a while. He was also someone who used the Argus app to track his steps. And, when he was finally charged his iPhone, he found that Argus had somehow gotten his movement data for four days after his battery died. This makes it seem as though the M7 motion coprocessor was able to function with the device turned off and using the reserve power in the battery for four days.
Of course, some will find this to be "creepy", but we try to be more nuanced on these issues. First of all, yes the iPhone continued tracking movements after the battery died, but it only did so because Glarznak had the device set to track him in the first place, which is something you can turn off if you are truly concerned. Also, as we have pointed out before when people complain about Google's policies, this isn't a matter of taking your data, this is a trade where you get value in return. Although, until Apple comments, we don't know what use this feature would be, because the M7 coprocessor is not tied to the GPS, so it would not be tied to "Find My Phone".
Whatever the explanation, it does prove that users need to be more knowledgeable about their devices, what information is tracked, and what steps to take to opt-out of tracking if that is what you want.