A Wall Street Journal investigation of 101 popular smartphone apps, which includes games and other software applications for the iPhone and Android devices--showed that 56 transmitted the devices' unique ID to other companies without permission from end users.

Another 47 apps transmitted data that could lead to identifying the phone's location, while five blatantly sent age, gender and other personal data to third parties.

In addition, iPhone apps sent more personal data than Android apps, and the apps sharing the most information included TextPlus 4, which sent the device's unique ID number to some eight different ad companies along with the phone's zip code and the user's age and gender on two of them. The popular music app, Pandora, running on both iPhone and Android also sent age, gender, location and phone identifiers to different ad networks.

While Apple (NASDAQ: AAPL) and Google (NASDAQ: GOOG) say they require apps to obtain permission before revealing certain types of information, such as location, the rules can be broken, the WSJ said. And while its possible to block or delete cookies on computers, smartphone users have few options, although they can opt out of phone tracking.

As such, these information sharing practices underscore the huge privacy risks for end users.  

For more:
- see this Wall Street Journal article

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