I'm guessing you're trying to prevent data theft, which I'm afraid is next to impossible. This is from a post someone else made on different forum:

For the USB devices, no. Your option there, and how companies with security needs of that magnitude deal with that issue, is to tightly lock down the clients and disable USB key use. (as well as CD burners, floppy drives if you still have those, etc) Again, that's going to require intrusive software, something like Landesk, + removing local admin so users can't take the software off.