Responding to a letter from legislators, Apple said it does not share users’ geolocation data with third parties without user permission and that the information is stored anonymously.

Reps. Edward Markey (D-Mass.) and Joe Barton (R-Tex.) sent Apple CEO Steve Jobs a letter last month with a list of questions about the company’s use of customers’ precise location information from its mobile devices and computers.

Earlier this year, Apple updated its privacy policy so that users were required to agree that the company and its “partners and licensees” could collect and store user location data.

Expressing concern about the change, the legislators asked Apple why the company started collecting the data and how the information is being used.

In its response from General Counsel Bruce Sewell, Apple said it began collecting location data in January 2008 in response to customer demand for location-based apps and programs, and has always provided its customers with the ability to control the location-based service capabilities of their devices.

Under the terms of its privacy policy, Apple said it cannot collect geolocation information without a user’s consent because individual users must activate the device’s location services and then allow specific applications (such as Google Maps) to utilize location data.

If a user chooses to enable the location services, the company does collect and store the data, the letter said. Apple collects “batched” sets of location data once every 12 hours, utilizing GPS satellite signals or cellular towers and Wi-Fi access points.

That information “does not include any information identifying the particular device or user,” according to Apple.

The recently launched iAd also collects longitude and latitude coordinates, which are converted into a zip code. While Apple does not share the coordinates or the zip code with advertisers, it does retain the information for six months, according to the letter.

To read Apple’s letter, click here.

Why it matters: In a statement, Reps. Markey and Barton thanked Apple for its response, but said greater transparency about geolocation data is important.

“The new challenges and concerns that present themselves with the collection and use of location-based information are particularly disconcerting,” Barton said. “While I applaud Apple for responding to our questions, I remain concerned about privacy policies that run on for pages and pages.” Reps. Markey and Barton are not alone – the issue has been addressed as part of the discussion to update the Electronic Communications Privacy Act, and Rep. Rick Boucher (D-Va.) included provisions relative to location data in his proposed privacy bill. Any company using geographic location data should pay close attention to the various developments, which we will continue to cover.