At Los Alamos, the sensitive computers are not even ON the Internet, the network is fibre optic only, and the boxes have no USB ports, serial ports or floppy drives to prevent removal of data.
So, to steal data, you actually have to STEAL it (e.g. crack case and remove HD, take pictures of screen, etc.). I guess a hard drive might fit in Sandy’s pants.
Or one of Waxman's nostrils.