iPhone keeps track of your movements

Stephen Withers
Thursday, 21 April 2011 09:52

Your IT - Mobility

The iPhone keeps a log of where it has been. A new open source program plots the data on a map for easy viewing. Privacy advocates are worried.

Another day, another privacy scandal. At least that's how it sometimes seems. Most of us know that smartphones can determine where they are, either by using a built-in GPS chip or from nearby cell towers and Wi-Fi access points - without that, location-based services couldn't work.

But few would expect their handsel was keeping a log of where it had been. That, it seems, is exactly what millions of iPhones have been doing. Furthermore, the file is transferred to the host computer during routine iTunes synchronisation.

The revelation was made by Pete Warden and Alasdair Allan, who have published information about the file along with an open source program that runs on a Mac and plots the locations on a map.

They discovered the issue while collaborating on location data visualisation projects: "it became clear that there was a scary amount of detail on our movements."

They note that they weren't the first to make this discovery - Paul Courbis described the method more than six months ago, but (perhaps because it was written in French) it did not gain much attention. It was also described by Christopher Vance around the same time.

The log records where and when - see page 2.