A report released at Where 2.0 conference about Apple's iPhone and iPad 3G capturing and sending users location data back to the company, resulted in -- Senator Al Franken subsequently sent a letter to Apple CEO Steve Jobs asking for an explanation.
Then, comes a revelation from the Wall Street Journal article: Apple and Google (with its Android devices) are both sending some location data from these devices back to their home servers.
Google who denied to comment, has later confirmed that this is indeed the case:
All location sharing on Android is opt-in by the user. We provide users with notice and control over the collection, sharing and use of location in order to provide a better mobile experience on Android devices. Any location data that is sent back to Google location servers is anonymized and is not tied or traceable to a specific user.
But, WSJ article also refers to data that isn't actually being anonymized by Google:
Google previously has said that the Wi-Fi data it collects is anonymous and that it deletes the start and end points of every trip that it uses in its traffic maps. However, the data, provided to the Journal exclusively by Mr. Kamkar, contained a unique identifier tied to an individual's phone.
Google explains that when a phone transmits data back to its servers some location data is actually assigned a unique identification number, but it says that this number is in no way associated with the device's IMEI, the user's name, or other information. In other words, they'd have a hard time associating a user with that data.