Users should be able to easily find out how much data they are storing that isn't part of an upload

[travis]

What
Users should be able to log into the web console and or use the CLI to see how much data they are storing that isn't part of an upload

Why
When users upload large files that fail mid-upload, they can end up in a situation where the uploads we show them don't fully account for the storage they're paying for. Users should be able to easily discover how much data they are storing that isn't part of an upload.

Cost
This will require a bit of product-level thinking and some novel UX, so this is probably a decent sized project.