Apple, breaking its silence over revelations that the App Store has been littered with apps that have unauthorised access to iPhone address books, has vowed to put a stop to the practice by requiring apps to explicitly ask permission to tap contacts.

An Apple spokesman issued this statement to AllThingsD

"Apps that collect or transmit a user’s contact data without their prior permission are in violation of our guidelines. We’re working to make this even better for our customers, and as we have done with location services, any app wishing to access contact data will require explicit user approval in a future software release."

It was revealed earlier this month that social networking app Path was grabbing iPhone contact information and sticking it on Path servers without permission, and since then, it has been shown that apps from even bigger name players like Facebook, Foursquare and Twitter take similar liberties.  Many of the app makers have reportedly since fixed the problem, which stems from their desire to hook users' up with other users in their contact lists. Some apps don't actually store the contact data on their servers, but questions have been raised about how safely the data is transported across the network.

Customer outrage about the situation prompted US Representatives Henry Waxman and G.K. Butterfield to issue a letter to Apple CEO Tim Cook yesterday about his company’s privacy practices. 

Apple has until 29 February to answer a series of questions from the Congressmen. 

Apple and other mobile phone companies caught the attention of Congress last summer as well regarding privacy concerns involving location tracking.