April 27, 2011 at 10:44 am

Apple Says It Uncovered One of the Location-Tracking ‘Bugs’

One week after the world learned that iPhones and 3G iPads were tracking their movements over the past year, Apple released a much-needed explanation about why the devices were logging users’ travel habits over the previous year — and, under the default setting, backing that data up on users’ computers without encryption, potentially exposing sensitive data to thieves, stalkers, and law enforcement.

In the explanation, posted below, Apple says it was not tracking users, merely storing the locations of the WiFi hotspots and cellular towers to which their devices connected over the past year in order to speed up the device’s GPS functionality, which is a crucial aspect of many promising apps. In addition, Apple claims that it (and, by extension, not researchers) uncovered the “bug” that caused this location data to be stored for an entire year.

This explanation will lay to rest some fears about why this data was being tracked. However, some might contest the way Apple blames user confusion and unintentional software bugs for the issue, which has arguable set location-reliant apps back a step by freaking everyone out:

1. The main reason people are so worried out about having their approximate locations over the previous year stored in unencrypted form on their phones and computers, according to Apple, is that “users are confused” by “very complex technical issues” surrounding the delivery of fast location-based services while protecting privacy. Granted, Apple owns up to not having educated consumers about this stuff, but it’s not just a matter of perception. Sensitive data was gathered and potentially exposed without users’ knowledge.

2. Apple’s devices were recording and backing up this location information for an entire year, which Apple says was due to “a bug we uncovered and plan to fix shortly” (our emphasis). Surely, it’s pure coincidence that Apple and the rest of the world discovered this bug at approximately the same time, in iOS 4 software that was released last June, right? Doubtful.

3. Apple says another bug caused it to record this information even with location services were turned off, and that it plans to fix that bug in the next version of iOS, so that the entire cache of locations gets deleted every time the user turns off location services. As with the year-long location record, it’s a mystery why this “bug” would still exist in the iPhone at this advanced stage of the game.

4. Apple doesn’t overtly accept blame for storing this location log in unencrypted form on the phone, or on the computer, possibly for legal reasons, but says it plans to encrypt the location log and cease backing the data up to computers entirely in the next version of iOS, which it says will arrive in the next few weeks.

Aside from those objections, however, Apple’s explanation provides some well-deserved clarity about what is going on here:

April 27, 2011

Apple Q&A on Location Data

Apple would like to respond to the questions we have recently received about the gathering and use of location information by our devices.

1. Why is Apple tracking the location of my iPhone?

Apple is not tracking the location of your iPhone. Apple has never done so and has no plans to ever do so.

2. Then why is everyone so concerned about this?

Providing mobile users with fast and accurate location information while preserving their security and privacy has raised some very complex technical issues which are hard to communicate in a soundbite. Users are confused, partly because the creators of this new technology (including Apple) have not provided enough education about these issues to date.

3. Why is my iPhone logging my location?

The iPhone is not logging your location. Rather, it’s maintaining a database of Wi-Fi hotspots and cell towers around your current location, some of which may be located more than one hundred miles away from your iPhone, to help your iPhone rapidly and accurately calculate its location when requested. Calculating a phone’s location using just GPS satellite data can take up to several minutes. iPhone can reduce this time to just a few seconds by using Wi-Fi hotspot and cell tower data to quickly find GPS satellites, and even triangulate its location using just Wi-Fi hotspot and cell tower data when GPS is not available (such as indoors or in basements). These calculations are performed live on the iPhone using a crowd-sourced database of Wi-Fi hotspot and cell tower data that is generated by tens of millions of iPhones sending the geo-tagged locations of nearby Wi-Fi hotspots and cell towers in an anonymous and encrypted form to Apple.

4. Is this crowd-sourced database stored on the iPhone?

The entire crowd-sourced database is too big to store on an iPhone, so we download an appropriate subset (cache) onto each iPhone. This cache is protected but not encrypted, and is backed up in iTunes whenever you back up your iPhone. The backup is encrypted or not, depending on the user settings in iTunes. The location data that researchers are seeing on the iPhone is not the past or present location of the iPhone, but rather the locations of Wi-Fi hotspots and cell towers surrounding the iPhone’s location, which can be more than one hundred miles away from the iPhone. We plan to cease backing up this cache in a software update coming soon (see Software Update section below).

5. Can Apple locate me based on my geo-tagged Wi-Fi hotspot and cell tower data?

No. This data is sent to Apple in an anonymous and encrypted form. Apple cannot identify the source of this data.

6. People have identified up to a year’s worth of location data being stored on the iPhone. Why does my iPhone need so much data in order to assist it in finding my location today?

This data is not the iPhone’s location data—it is a subset (cache) of the crowd-sourced Wi-Fi hotspot and cell tower database which is downloaded from Apple into the iPhone to assist the iPhone in rapidly and accurately calculating location. The reason the iPhone stores so much data is a bug we uncovered and plan to fix shortly (see Software Update section below). We don’t think the iPhone needs to store more than seven days of this data.

7. When I turn off Location Services, why does my iPhone sometimes continue updating its Wi-Fi and cell tower data from Apple’s crowd-sourced database?

It shouldn’t. This is a bug, which we plan to fix shortly (see Software Update section below).

8. What other location data is Apple collecting from the iPhone besides crowd-sourced Wi-Fi hotspot and cell tower data?

Apple is now collecting anonymous traffic data to build a crowd-sourced traffic database with the goal of providing iPhone users an improved traffic service in the next couple of years.

9. Does Apple currently provide any data collected from iPhones to third parties?

We provide anonymous crash logs from users that have opted in to third-party developers to help them debug their apps. Our iAds advertising system can use location as a factor in targeting ads. Location is not shared with any third party or ad unless the user explicitly approves giving the current location to the current ad (for example, to request the ad locate the Target store nearest them).

10. Does Apple believe that personal information security and privacy are important?
Yes, we strongly do. For example, iPhone was the first to ask users to give their permission for each and every app that wanted to use location. Apple will continue to be one of the leaders in strengthening personal information security and privacy.

Software Update
Sometime in the next few weeks Apple will release a free iOS software update that:

  • reduces the size of the crowd-sourced Wi-Fi hotspot and cell tower database cached on the iPhone,
  • ceases backing up this cache, and
  • deletes this cache entirely when Location Services is turned off.

In the next major iOS software release the cache will also be encrypted on the iPhone.



  • http://www.techonologyreview.blogspot.com Technology review

    People may not notice it, Android OS is not the only product to collect our location data, Google street view cars, Google Maps, Chrome all have been recording our information. I have made a few online tools to query our location data in Google server, and find that Google actually knows more than we think.
    You can use the the tool to check if Google is watching you as well here http://cellphonetrackers.org/gsm/ip-tracker.php http://cellphonetrackers.org/gsm/gsm-tracker.php