You know, it's creepy for a single person too though. I know you're storing only metadata to build an index, but that is still a lot and I think for most it causes a big feeling of unease.

In my opinion your service would be great if it were fully-local. This would also open up the path to full-text search for documents, without being creepy. I'm not expecting you to do that for free of course, I mean as a paid product. (Haven't dug into your current pricing details)