'Phantom Data' or usage tracking I wonder? Has anybody read the license agreement for WP7? (I haven't, just wondered if it mentioned usage tracking in there anywhere)
One of the teachers here has the HTC HD7 and asked me why he had used all of his 500mb in less than a month.
He claimed to be only a light user, so would suspect its this issue. As a precaution I turned off push etc.
There is a little voice in my head saying 'why am I not surprised'...