It's not just your phones. Today, the Wall Street Journal reports "Apple gathers information from some Apple Macintosh computers connected to Wi-Fi networks, and Google collects data from Wi-Fi-connected computers that use Google's Chrome browser or search 'toolbar.'" Sometimes the companies ask users to collect this data, sometimes, the companies can't ask. What happens to this data? We're not always sure.
From the Journal:
Google says the collection process works like this: the computer scans the area around itself to find available Wi-Fi networks, and then the Google Toolbar or the Web browser sends the Wi-Fi access-point information back to Google's location database. Google "anonymizes" and aggregates the information.
Apple disclosed its location-gathering practices in a letter last year to Reps. Edward Markey (D., Mass.) and Joe Barton (R., Texas). According to the letter, Macintosh computers running the "Snow Leopard" operating system send the company information about a computer's location if the user is connected to the Internet through a Wi-Fi network and is using location-based services, such as asking the computer to automatically identify the local time zone.
The data is "collected anonymously, and is stored in a database accessible only by Apple," the letter said. Users can prevent the information from being collected by turning off "location services" in the "security" menu under "system preferences" on the computer, it said.