Congress members will not relent on their latest push for mobile app privacy. On Thursday, House representatives Henry Waxman (D-CA) and G.K. Butterfield (D-NC) sent a joint letter to 34 social app sellers who market their offerings through Apple's App Store in order to request information about their data collection practices. The goal is to "better understand what, if any, information these particular apps gather, what they do with it, and what notice they provide to app users."

The app-makers in question weren't necessarily selected because they had been caught siphoning address book data or private photos to a remote server without permission—though that kind of app behavior is the reason the two Congressmen are requesting more information. According to Waxman and Upton, the 34 individuals—which include Apple CEO Tim Cook for the location-sharing app "Find My Friends"—were selected for being associated with a social networking app included within the App Store's "iPhone Essentials" list. (The full list of letter recipients is available on the Energy & Commerce committee's website.)

In the letter, the two Congressmen ask questions like "how many times was your iOS app downloaded," "did you have a privacy policy in place at the end of February 2012," "has your iOS app transmitted [ ] any other information from or about a user's device," and a request for descriptions of what has been done to any data that has been transmitted or stored. The developers are given a deadline of April 12, 2012 to respond—exactly three weeks from today.

The request for information comes after social networking service Path was caught transmitting users' address book data to a remote server without explicitly asking for permission—a discovery that led to numerous other apps being called out for the same behavior. (For example, Foursquare, Instagram, Facebook, Twitter, and Voxer were all found to be sending some or all of a user's address book data to their respective servers.) The same month, a similar "loophole" for photos, calendar data, music, movies, and more was discovered, though Apple has implied publicly that it may modify the APIs to require explicit user permission for access to user information.

This isn't the first Congressional inquiry made over mobile apps and user data. Waxman and Butterfield sent a joint letter to Tim Cook immediately following the Path controversy in February, but now it looks like they're trying to dig in even further by going straight to the developers themselves. But although app makers are the ones getting themselves into trouble lately, the app developers we spoke to in February agreed that Apple needs to overhaul iOS user information security before there's any kind of consistency in app behavior. As Stand Alone's Chris Cieslak told Ars at the time, "[a]t this point, Apple’s going to have to revamp permissions dialogs like they had to for notifications in iOS 5."

Listing image by Photograph by Pete O'Shea