According to a new study by Duke University, Penn State University, and Intel Labs, several popular free Android apps have been sharing personal information about user location with advertisers, and doing so without user consent.

They used TaintDroid to test 30 popular free Android applications selected at random from the Android market and found that half were sending private information to advertising servers, including the user's location and phone number. In some cases, they found that applications were relaying GPS coordinates to remote advertising network servers as frequently as every 30 seconds, even when not displaying advertisements. These findings raise concern about the extent to which mobile platforms can insulate users from unwanted invasions of privacy.

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