Apple responds to iPhone location data controversy


27 Apr 2011

Apple has responded to the location data issues on its iOS devices, saying the database is a cache of crowd-sourced Wi-Fi hotspots and cell towers. It will make changes to this in a software update.

Apple addressed the most frequently asked questions on the matter in a statement about the controversy over the discovery that 3G enabled iPhones and iPads running iOS 4 were keeping track of their owners’ locations.

The statement said Apple was not tracking the location of user’s iPhones and do not ever have plans to do so.

Apple said the iPhone was not logging users’ locations, but was “maintaining a database of Wi-Fi hotspots and cell towers around your current location” to help a user’s device calculate its location when requested.

“Calculating a phone’s location using just GPS satellite data can take up to several minutes,” read the statement.

“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,” read Apple’s statement.

Apple said that entire crowd-source database is too big to be put on a single iPhone, so Apple downloads an appropriate cache onto each iPhone, which gets backed up to iTunes whenever the phone syncs with it.

“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 100 miles away from the iPhone,” said Apple.

Apple said this data is sent anonymously and encrypted to them, meaning they cannot identify an individual’s location.

Bugs

Apple acknowledged the fact this cache of the Wi-Fi hotspot and cell tower database is stored for up to a year is a bug, noting it doesn’t think the iPhone needs to store more than seven days of this data.

The company also acknowledged the iPhone should not be collecting this data when the user deactivates Location Services, which Apple also said was a bug.

Apart from the collection of crowd-source Wi-Fi hotspot and cell-tower data, Apple is also collecting anonymous traffic data to build a database to provide an improved traffic service for iPhone users.

The company said location data is not shared with third parties or ads unless the user explicitly approves this.

In the coming weeks, Apple will release a software update for iOS which will reduce the size of the Wi-Fi hotspot and cell-tower database cached on the iPhone. The update will cause the iPhone to stop backing up this cache onto iTunes and will delete the cache entirely when Location Services have been turned off. The cache will also be encrypted on the iOS device.