Reps. Henry Waxman (D-Calif.) and G. K. Butterfield (D-N.C.) have sent letters to 34 top mobile software companies to find out "what, if any, information these particular apps gather, what they do with it, and what notice they provide to app users."
The companies they've hit up for information include Apple, Facebook, Twitter, Foursquare and Turntable.fm. The five companies have apps that appear in the "social networking" category of "iPhone essentials" in the App Store.
Developers are being asked for specific details about their privacy policies; whether their software has transmitted data from users' address books, photo galleries, GPS tags and other sensitive information; and details of what the companies are doing to protect the privacy of users.
The pair will use the information as a basis of a "fact-finding mission" to learn more about the security and privacy practices in the world of app development.
Over the past few months, developers have come under fire for apps that allegedly transmit users' private data without their knowledge. Reports from The New York Times suggested that apps on both Apple's iOS and Google's Android platform are transmitting users' private data unbeknownst to them.
Sen. Schumer (D-N.Y.) has asked the Federal Trade Commission (FTC) to investigate both companies' privacy practices, and President Obama has suggested the adoption of a "Consumer's Bill of Rights" for online data.
Waxman and Butterfield were also signatories to a January letter to Google demanding to know more about the company's recent privacy policy changes.