Not long ago, Google found itself in the hot seat when a team of researchers found a large sample of Android apps distributing personal data without users' permission.
Now it looks like Apple iPhone apps are just as guilty, if not worse.
According to a study of 101 mobile applications conducted by the Wall Street Journal, iPhone apps distribute more personal data without the users' permission than Android apps.
The "leakiest" apps, according to the Journal, include Pandora, Grind, Paper Toss, and TextPlus 4, which sent age, gender, ZIP codes, and user IDs to multiple ad networks.
The most commonly submitted information, usually sent back to either the app maker or sold to an ad network, is the phone's unique user ID number, which can give companies valuable information on what an owner does with his or her phone.
Unlike Web sites, mobile apps don't have privacy policies, the Journal's Julia Angwin said in a video report, which you can watch below.
To conduct the test, the Journal hired a technology consultant from Electric Alchemy, a software security firm, to analyze 101 of the most popular apps on the Apple App Store and Android Marketplace; 50 each for the iPhone and Android and the Journal's's iPhone app. The consultant tested the apps on an iPhone 3G and a Samsung Captivate.
Business Insider suggests the Journal may have been exaggerating the threat of transmitting data back to an ad network.
"The WSJ story isn't clear as to when the data is transmitted back to the app maker, or back to third party ad networks or analytics firms, which is quite different," writes Pascal-Emmanuel Gobry. "Ad networks and analytics software take anonymous data and use it to perform targeting or find out how you use your device...targeting and analytics have been online for fifteen years now and it doesn't seem to have hurt anybody."
Apple claims it has over 300,000 apps in the App Store, while Android Marketplace hit 100,000 in October.