Alasdair Allan and Pete Warden
A visualization of iPhone location data atored in a file on the phone.

I used to say, "Who knew Big Brother would be voluntary?" about Facebook.

Now I should add, "Who knew Big Brother put a spy in your hot luxury phone?" after the Guardian reports (iPhone keeps record of everywhere you go), "British researchers on Wednesday revealed that iPhones (and 3G-enabled iPads) keep track of where you go, including timestamps, on a file that is backed up on your computer and shifted onto any new iPhone or iPad you get. Apple hasn't said why the file is created or whether the tracking can be prevented."

The scientists, Alasdair Allan and Pete Warden, are reporting their findings in detail on the O'Reilly Radar site: Got an iPhone or 3G iPad? Apple is recording your moves , and will present them at the O'Reilly Where 2.0 conference in San Francisco:

Today at Where 2.0 Pete Warden and I will announce the discovery that your iPhone, and your 3G iPad, is regularly recording the position of your device into a hidden file. Ever since iOS 4 arrived, your device has been storing a long list of locations and time stamps. We're not sure why Apple is gathering this data, but it's clearly intentional, as the database is being restored across backups, and even device migrations.

It's broken down lucidly:

What information is being recorded?

All iPhones appear to log your location to a file called "consolidated.db." This contains latitude-longitude coordinates along with a timestamp. The coordinates aren't always exact, but they are pretty detailed. There can be tens of thousands of data points in this file, and it appears the collection started with iOS 4, so there's typically around a year's worth of information at this point. Our best guess is that the location is determined by cell-tower triangulation, and the timing of the recording is erratic, with a widely varying frequency of updates that may be triggered by traveling between cells or activity on the phone itself.

How can you look at your own data?

We have built an application that helps you look at your own data. It's available at petewarden.github.com/iPhoneTracker along with the source code and deeper technical information.

What can you do about this?

An immediate step you can take is to encrypt your backups through iTunes (click on your device within iTunes and then check "Encrypt iPhone Backup" under the "Options" area).

If you own either iThing, there's more for you there.

And more from the Guardian,

"Apple has made it possible for almost anybody - a jealous spouse, a private detective - with access to your phone or computer to get detailed information about where you've been," said Pete Warden, one of the researchers.

Only the iPhone records the user's location in this way, say Warden and Alasdair Allan... "Alasdair has looked for similar tracking code in [Google's] Android phones and couldn't find any," said Warden. "We haven't come across any instances of other phone manufacturers doing this."

...The location file came to light when Warden and Allan were looking for a source of mobile data. "We'd been discussing doing a visualisation of mobile data, and while Alasdair was researching into what was available, he discovered this file. At first we weren't sure how much data was there, but after we dug further and visualised the extracted data, it became clear that there was a scary amount of detail on our movements," Warden said.

It would be so typical for an engineer to have created that file simply because he could, with a myopic understanding of how such data might be used against the phone's user.

In a closed pay-to-play system, expect anything.