I was reading an article in the BBC news website when I came across the following statement:
"Nothing in a SCIF is allowed to operate on a remote control because that's a frequency that can be tapped," he says. "Much of what is distributed is done on fibre, not copper as fibre as yet can't be hacked into."
The SCIF is a secure tent used by the President of the United States to take confidential phone calls/conferences when he on tour somewhere. They are designed to prevent eavesdropping of the confidential information. However the follow up statement that Fibre cannot be hacked into is total rot. It is in fact very easy. strip back the insulation covering the fibre, bend it in a radius of about 2 cm and attach a laser sensor. Bob's your uncle, you can read the data traffic as if you are plugged in to the fibre. I've see this done live at a security demonstration.
Hopefully any such communication to the SCIF via copper or fibre will be end-to-end encrypted to defeat any such line tapping.