101 popular smartphone Apps were examined on both iPhone and Android, and it was found that many of those Apps sent user's data without the device owner's knowledge or so much as a warning or any sort of consent.
56 sent out the device's unique ID, while 47 of the Apps sent location information (which personally doesn't sound as bad as some of the other stuff. I'd rather get ads for my local Pizza Hut than some sandwich shop in Manhattan.)
Now, some of these Apps are sending the UID (which is a unique number to each iOS device that cannot be changed or removed) age, gender and location information are all things that can be sent out. Even Apps such as Paper Toss and Pandora are offenders as well.
This is, to us at least, one more reason to jailbreak your phone.
PrivaCy is a jailbreak application (more info) that Saurik put together that allows you to keep that data to yourself.
Install the app from Cydia and go to your device Settings.
From there you will see Privacy:
You will have to turn off the usage statistics for each: Flurry, Medialets, Mobclix, Pinch Media.