Why do people continue to harp on flash drives specifically as dangerous?
If you are worried about viruses, they can spread by any removable media. The real problem is Windows enables autorun by default on USB and CDs, so even conscientious users can spread viruses accidentally. Blame Microsoft and disable autorun, don't blame the drives.
If you are worried about data theft, disable all removable media. If it is that big of a deal, you have to be concerned about any device plugged into a port on the computer, as you could put a sniffer in between the ethernet port and the network then transfer the file over the network and capture it as it goes. Again, don't just disable flash drives.