Apple's iPhones and Google's Android smartphones regularly transmit their locations back to Apple and Google, respectively, according to data and documents analyzed by The Wall Street Journal -- intensifying concerns over privacy and the widening trade in personal data.
Google and Apple are gathering location information as part of their race to build massive databases capable of pinpointing people's locations via their cellphones. These databases could help them tap the $2.9 billion market for location-based services -- expected to rise to $8.3 billion in 2014, according to research firm Gartner.
In the case of Google, according to new research by security analyst Samy Kamkar, an HTC Android phone collected its location every few seconds and transmitted the data to Google at least several times an hour. It also transmitted the name, location and signal strength of any nearby Wi-Fi networks, as well as a unique phone identifier.
Google declined to comment on the findings.
Until last year, Google was collecting similar Wi-Fi data with its fleet of StreetView cars that map and photograph streets world-wide. The company shut down its StreetView Wi-Fi collection last year after it inadvertently collected e-mail addresses, passwords and other personal information from Wi-Fi networks. The data that Mr. Kamkar observed being transmitted on Android phones didn't include such personal information.
Apple, meanwhile, says it "intermittently" collects location data, including GPS coordinates, of many iPhone users and nearby Wi-Fi networks and transmits that data to itself every 12 hours, according to a letter the company sent to U.S. Reps. Edward Markey (D-Mass.) and Joe Barton (R-Texas) last year.
Apple didn't respond to requests for comment.
Read more on data transmissions from Apple and Google at The Wall Street Journal.