"Most people prefer to entrust a bank with their money as opposed to their own hiding place of choice based on similar reasoning: the bank by looking after money for many customers can probably do a better job of it than they can for themselves."

Yes, and there are all sorts of legal frameworks that make sure that banks do their job. At the moment, Google could disappear overnight and there are no guarantees on what happens with user data.

It's a simple case of technology developement outstripping legal frameworks. I'll start trusting external agencies with my data when the law catches up.