It's called "locations services," and many applications use it to provide location-based information for various iPhone apps.
Customers with concerns about a phone recording and even broadcasting their location have learned to turn off location services for particular applications except those needed to enable mapping programs and security measures.
Those actions do not disable a deeper setting in the Apple IOS 7 mobile operating system which tracks a user's frequent locations. If the wrong person got his hands on that device and was able to access it, he can easily learn the daily habits of the phone's owner.
Students at the University of Washington volunteered their phones to see how easy it can be to see where the device has been. The frequent locations setting creates a map, and tapping on a specific locations reveals the dates and times of a particular visit and even how long you were there.
The students were taken aback that it was so easy to track their history.
"That's kind of crazy," Sebastian Aste said. "It's interesting how accessible your life can be."
"The chance that that would happen, that someone would take my phone and try and track me down seems really, really small," Abby Skifstad said. "But it makes me uneasy thinking about that."
Apple is not the only phone manufacturer with this kind of setting. Google does something similar with Android phones where opting in to any location based app, like Google Now or Google Maps, turns on the phone's location tracking.
A Google presentation posted on YouTube boasts that "Google Now is smart enough to check current traffic conditions and has prepared an alternate route for your commute."
Hanson Hosien is the director of UW's Digital Media Master's program, where every day he teaches the pluses and minuses of new media.
"You're getting something in return for giving up where you are," Hosien said. "Most of us don't even think about the quid pro quo. We just receive it and not really think about the privacy implications."
The privacy attorney for Washington's chapter of the American Civil Liberties Union, Doug Klunder, says the implications are serious.
"Once you consent on your phone to give your location service information, all bets are off," Klunder said. "They can do with it whatever they want."
It's a risk some UW students said they are willing to take.
"It doesn't really bother me," Ward said. "There's also like safety things like walking around the U District -- sometimes not the safest. So if there's an emergency, they can find me faster because of this."
Apple's terms say the frequent location data "is kept solely on your device and will not be sent to Apple without your consent." But the next operating system due out this fall may do just the opposite.
With IOS 8, developers with access to the software say all location information will go through Apple. The system will falsify the phone's location to everyone else except to Apple.
Privacy advocates may welcome that move because it makes it harder for their parties to share that information, but Apple will still know where its users are located.
Android users are tracked as well but do not have the ability to turn off location tracking. Every time an Android user agrees to the terms of an application that accesses the phones location, the user agrees to turn on the phones location tracking ability.
The way to avoid that is by never agreeing to the terms of any app that accesses the phones location, but the reality is very few people will want to do that.
Learn how to disable location tracking on an iPhone here.