Microsoft: Windows Phone 7 Data Glitch
Microsoft stated last week that they are investigating the issue of Windows Phone 7 devices inexplicably sending data over the 3G networks, even while the phones were connected over WiFi. In one case a user claimed as much as 50 GB of data was sent with authorization. Obviously this problem will have an impact on the users data-plan and cost however Microsoft has not addressed any type of compensation for the issue claiming the issue is related to a third-party app.
Unauthorized Data Sent Over the 3G Network on Windows Phone 7 Smartphones