"Law enforcement agencies have known since at least last year that an iPhone or iPad surreptitiously records its owner's approximate location, and have used that geolocation data to aid criminal investigations.
Apple has never publicized the undocumented feature buried deep within the software that operates iPhones and iPads, which became the topic of criticism this week after a researcher at a conference in Santa Clara, Calif., described in detail how it works. Apple had acknowledged to Congress last year only that "cell tower and Wi-Fi access point information" is "intermittently" collected and "transmitted to Apple" every 12 hours.
At least some phones running Google's Android OS also store location information, Swedish programer Magnus Eriksson told CNET today. And research by another security analyst suggests that "virtually all Android devices" send some of those coordinates back to Google."