I posted a blog a while back about this, but after showing people the error during class and
seeing the 'oh my gosh' look in their eyes, it was evident that I hadn't clearly explained the problem.
Here is the scenario:
1. You force Check out in a document library
2. A user mass uploads files
3. Those files are now in a 'Checked-out state'
4. The administrator (or anyone else) CANNOT see those files until they are checked in the first time.
5. Until the files are checked-in, only that user can see them.
A user could consume the entire site quota, yet the administrator won't know why. I will try to post some pics of this later today.
Here's the original post.