So your solution for data synchronization is a manual sync?

No, that's what I said. I said syncing over the home network.

Let me ask you this. What's the safer way of handling your data. Both done 100% automatically.

Computer<-->Phone<-->Other Devices

...or

Computer<-->Windows Live<-->Phone<-->Windows Live<-->Other Devices

Adding in the "Windows Live" to the automatic syncing is not needed. It can be done 100% transparently to the user, 100% automatic, 100% secure by using a 100% home network connection.

Not only would there be issues with local networking firewalls causing data transfer issues with the syncs over the network it would require you to be on the wifi. What if I didn't turn on my wifi?

Those issues would prevent the cloud from syncing the device

I don't see what the problem is.

Single point of failure for that person data millions of users, perhaps even hundreds of millions of users. There will come a day, perhaps not for many years, when one of these major stores of personal data is broken into. Everyone's personal business will be known to a party with less than benevolent intentions.

The loss of personal data happens all the time on the internet. Usually it's in the form of credit info, which can be quite damaging to a person when in the wrong hands. Fortunately for us, the worst of the breaches happen to "only" a few million people at a time. There will come a day when a major world wide hack happens to someone like Microsoft and hundreds of millions of people will be affected.

It's not that I don't trust Microsoft, that's not the point. I just understand that having a single point of failure for personal data is a TERRIBLE idea.