London: Do you know that dozens of popular iPhone applications could be secretly spying on what you do with them.
More than half of the programs and games for smartphones sent data back to the private company once they had been downloaded, a study has found.
It found that of the 101 applications tested, 56 transmitted the phone`s individual number to a private company in some way, known as the Unique Device Identifier or UDID.
Some 47 sent the phone`s location and five sent age, gender and other personal information, a newspaper reported.
The applications include the wildly popular Angry Birds game and music identifying software Shazam, which comes pre-installed on every iPhone.
More data was sent back about a user`s location on the Apple`s iPhone than Google`s Android smartphone, the research discovered, even though both companies have promised not to let such practices take place.
Armed with this information, firms, including Google, track the individuals` movements and sell personalised ad for which they can make more money than regular ones.
The research was carried out in the US but it would apply to users downloading applications from anywhere in the world.
Michael Becker of the US-based Mobile Marketing Association said the advantage of mobile phones for advertisers is that they are always with us.
"It`s always on," he said. "In the world of mobile, there is no anonymity," he said.
The research by the Wall Street Journal found that smartphone users had no way of stopping the tracking, unlike on a computer where you can disable the monitoring software, known as `cookies`.
Typical of the problem was Angry Birds which sent the phone`s UDID to the game`s makers Electronic Arts.
Pandora, the popular music application, sent gender, location, age and the phone ID to a string of advertising networks.
Android and iPhone versions of a game called Paper Toss, where players try to throw paper wads into a bin, each sent the phone`s ID number to at least five ad companies.
Applications became wildly popular with the advent of smartphones and when Apple opened its App store in 2008. Now more than 300,000 are available.