Black Lines
This isn’t really related to science fiction; it’s more of a high-tech thriller story. Bill at Switchback tells the tale of a construction crew that hit a buried fiber-optic cable, prompting an immediate, unexpected response from men in black SUVs:
Georgelas assumed that he was dealing with the federal government and that the cable in question was “black” wire — a secure communications line used for some of the nation’s most secretive intelligence-gathering operations.
“The construction manager was shocked,” Georgelas recalled. “He had never seen a line get cut and people show up within seconds. Usually you’ve got to figure out whose line it is. To garner that kind of response that quickly was amazing.”