To provide a lightweight utility that will secure a SharePoint server at the portable media level to Prevent unauthorized data copying and malicious content insertion. Read this security focus article on new USB threats (specifically regarding a credit union).
It is important when protecting your SharePoint environment to ensure that you harden your server at all tiers of data copying and injection. This involves securing sections of your server which can accept other types of media besides providing access over a network. The most common portable media storage types that you are going to find available on typical servers running SharePoint:
CD/DVD Tray
USB Device
Floppy Drive