To me this would only be a problem if someone was actually looking at my data - they aren't. Even with Google, who are probably the worst company for collecting data, they go to extraordinary measures to make sure that their staff don't have access to it. The fact that they have all this data, is only going to be a problem if you do something illegal, and are the subject of an investigation. If you are accused of something you didn't do, the data could actually help prove your innocence.
In truth, your data is far more vulnerable in an old school filing system, and you are far more likely to have your personal information spread around by hiring a person as a PA.