Sensitive Compartmented Information Facility (pronounced “skiff”), a U.S. Department of Defense term for a secure room. It can be a secure room or data center that guards against electronic surveillance and suppresses data leakage of sensitive security and military information. SCIFs are used to deny unau­tho­rized per­son­nel, such as for­eign intel­li­gence ser­vices or corporate spies, the oppor­tu­nity for unde­tected entry into facil­i­ties for the exploita­tion of sen­si­tive activ­i­ties.

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when technologies exist that allow you to know what someone is saying inside a soundproof room by pointing a laser at a window, or know what is being displayed on a computer screen by driving by in a van with EMF detection equipment that can reconstruct the image by leaked EMF radiation, you need a special room to read and talk about things.

It's basically a room vault that passed a lot of different security requirements used to work with classified data.

Wtf are you doing here if you don’t know what a SCIF is?