Illinois Atty. Gen. Lisa Madigan on Monday requested meetings with both Apple and Google Inc., which also records users' location data through its Android smartphones. Last week, two researchers drew attention to a data file embedded on Apple devices that apparently keeps tabs on years' worth of user location data.
"I want to know whether consumers have been informed of what is being tracked and stored by Apple and Google and whether those tracking and storage features can be disabled," Madigan said in a statement.
Madigan's letter followed requests to Apple last week by U.S. Sen. Al Franken (D-Minn.) and Rep. Edward J. Markey (D-Mass.). Privacy regulators in France, Italy and South Korea are also looking into the matter, according to news reports.
Apple has not responded to requests for comment on the tracking, which received wide attention last week.
Apple told lawmakers last year that its mobile devices send batches of user location data back to the company twice a day. The data do "not reveal personal information about any customer," Apple said at the time.
Google too has acknowledged it collects location data from users' mobile devices in order to be able to provide and improve applications like Google Maps, which helps users navigate city streets.
The company said in a statement that users are notified before their location data are collected and are offered the chance to turn off the function. Like Apple, Google has said that the location data it collects are stored anonymously.
Apple has also said that users can stop tracking features by turning off all location-based services on their phones, but a report in the Wall Street Journal last weekend contended that the data were collected even after those services were disabled.
Times staff writer Jessica Guynn contributed to this report.