The requests from Franken and Illinois Attorney General Lisa Madigan follow recent reports that Google and Apple have been collecting data about the location of Android and iPhone users without their permission. While both companies ask permission before collecting the location data required for certain applications, the reports, , show the companies also collect location information when not required to do so by an application.

Madigan to explain what information they store, for how long and what it's used for. "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," she said in a statement.

Franken on Monday asked representatives from Google and Apple to about protecting mobile privacy.

The lawmakers aren't the only ones concerned about the data collection. that charges Apple with fraud over the alleged data collection. South Korea and some countries in Europe have also .

In addition, Congressman Edward Markey, a Democrat from Massachusetts, said he to Apple's CEO last week with questions about the company's data collection practices.