You're ooking at it from a different point of view than the author. While there are privacy concerns in handing over such data to a 3rd party, there is some merit in being able to conveniently access data from multiple devices without the headaches of managing multiple instances of it.

I think given the choice, most consumers usually pick the later since convenience trumps privacy concerns...that is until privacy/ownership bites them in the behind...

Although, I would prefer to have that choice rather than being forced to go one way or the other...