>>90220

TEMPEST is also a class of building that prevent leakage of electronic signals. I once worked in a Tempest class building.

With the right spying tools, someone printing a document can have that document reproduced by a spy that is hundreds of yards away. The printing cable leaks signals that can be reconstructed.

A spy can see exactly what you see on your PC monitor hundreds of yards away with the right equipment. Monitor cables leak signals.