You need optical media to transfer content from one network to another without setting off alarms. The network admin knows if you plug in mass storage devices within about 2 seconds. Mass storage devices require a mounting process that communicates with both the bios and the OS. The OS will then send an alert to a known point on the network, and if configured directly will respond to the switch at the local network which will drop the subnet. If you are dumb enough to pop a USB device in everybody in your office will know in seconds as they lose their connection. Then your boss will get scolded and you will get stuck with remedial training. It is pretty damn embarrassing like wearing a dunce cap. They may not always know who the offending person is, but they will have the IP of the offending terminal and a hardware signature of the offending device.