USBs
Who in the SECRET or TOP SECRET environment allows access to USB ports?
It might be necessary on certain machines but only with logging (electronic and wet ink) and witnesses.
Also any stick must be an encrypted stick.
I know of one American defense company that allowed (without realising it) changing the file name extension to get through the blocks. This is now handled by other protection systems. But this was after some secrets had beed stolen.
Amazing!