[sandworm101]

TEMPEST was also the codename of the NSA project for leveraging emissions. And it has become code for machines modified to protect against such things. So a "tempest computer" (if you ever see one) is a computer hardened against emissions.

[na85]

They're stupid expensive, those machines. A lot of places are finding that it's less expensive to maintain an EMSEC zone and run COTS equipment.

[sandworm101]

I've heard about them being used for an opposite reason. Rather than for security, they are used in places where you don't want to risk them interfering with other equipment, like a room with radar equipment that might be sensitive.