Privacy watchdogs are demanding answers from Apple Inc. about why iPhones and iPads are secretly collecting location data on users -- records that cellular service providers routinely keep but require a court order to disgorge.
Whether other smart phones and tablet computers are logging such information on their users remained unclear. And this week's revelation that the Apple devices do wasn't even new -- some security experts began warning about the issue a year ago.
But the worry prompted by a report from researchers Alasdair Allan and Pete Warden at a technology conference in Santa Clara raises questions about how much privacy you implicitly surrender by carrying around a smart phone and the responsibility of the smart phone makers to protect sensitive data that flows through their devices.
Much of the concern about the iPhone and iPad tracking stems from the fact the computers are logging users' physical coordinates without users knowing it. That information then is stored in an unencrypted form that would be easy for a hacker or a suspicious spouse or a law enforcement officer to find without a warrant.
Researchers emphasize that no evidence shows that Apple itself has access to this data. The data apparently stays on the device itself and computers to which the data is backed up. Apple didn't immediately respond to an Associated Press request to comment.
Tracking is a normal part of owning a cell phone. The controversy, however, lies in what becomes of that data.
A central question is whether a smart phone should act merely as a conduit of location data to service providers and approved applications -- or as a more active participant by storing the data itself, to make location-based applications run more smoothly or help better target mobile ads or any number of other uses.
Location data is some of the most valuable information a mobile phone can provide, since it can tell advertisers not only where users have been, but also where they might be going -- and what they might be inclined to buy when they get there.
Allan and Warden said the location coordinates and time stamps in the Apple devices aren't always exact, but appear in a file that typically contains about a year's worth of data that when taken together provides a detailed view of users' travels.
"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," they wrote in a blog posting announcing the research.
Allan said in an e-mail to AP that he and Warden haven't looked at how other smart phones behave in this regard, but noted an investigation into the suspicion that phones that run Google Inc.'s Android software might behave in a similar way.
Google did not immediately respond to a request for comment.
Alex Levinson, a security expert, said the tracking by Apple's devices isn't new -- or a surprise to those in the computer forensics community.
The Apple devices have been retaining the information for some time, but it was kept in a different form until the release of the iOS 4 operating software last year, Levinson, technical lead for the Katana Forensics firm, wrote on his blog.
The the location-data file on the phone is alarming because it's unencrypted, the researchers said, which means that anyone with access to the device can see it.
The issue has prompted several members of Congress to write letters asking Apple, based in Cupertino, Calif., to answer questions about the practice.
Sen. Al Franken, D-Minn., said it raises "serious privacy concerns," especially for children using the devices, since "anyone who gains access to this single file could likely determine the location of a user's home, the businesses he frequents, the doctors he visits, the schools his children attend and the trips he has taken -- over the past months or even a year."