In the words of one of the former officials, the CIA had “fucked up the firewall” between the two systems.
U.S. intelligence officers were also able to identify digital links between the covert communications system and the U.S. government itself, according to one former official — links the Chinese agencies almost certainly found as well. These digital links would have made it relatively easy for China to deduce that the covert communications system was being used by the CIA. In fact, some of these links pointed back to parts of the CIA’s own website, according to the former official.
“People died because of that mistake.”