Over the weekend, the Wall Street Journal revealed how they did an investigation on some of the most popular iPhone and Android applications to see what kind of data is sent to advertisers. It turns out that of the 101 popular apps that the WSJ looked at, over half was sending out unique device identifiers (UDID) to advertising companies. Some applications like Pandora had even sent out the age, gender, and location of users. However some of these apps send out data in batches in order to keep it anonymized.
One of the apps that sent out the most data is TextPlus 4, a text messaging app. TextPlus 4 sent out the phone’s unique ID number to 8 different ad companies along with the zip code, age, and gender. The Pandora Android and iPhone application sends out UDIDs, age, gender, and location to different ad networks. And Paper Toss sends out the phone’s ID information to at least 5 ad companies.