The File Vault gives you access to activity and usage reports. Activity reports allow you to see specifically who has logged in and then what files they have downloaded or uploaded. Usage reports allow you to see how how many files each client has and how much space those files are taking up overall. These two handy reports allow you to keep a good thumb on your file vault system. Here is how to view each.
When logged into the File Vault, click on the More button.
Now choose Activity Log
You can look at the data related to a specific client by clicking on the “All Clients” drop-down menu and choose the client who’s data you want to see.
Follow the same procedure above except you will choose Usage Report instead. You will then get a view of Account Name, Account Type, Space Used, and the Number of Files.