Khalid Sheik Mohammed masterminded the 9/11 attacks. According to a former CIA official, he later masterminded a vacuum cleaner. Why would the CIA approve a terrorist’s weird request to design a household cleaning device? “‘We didn’t want them to go nuts,’ the former senior CIA official said, one of several who spoke on condition of anonymity because they were not authorized to talk about the now-shuttered CIA prisons or Mohammed’s interest in vacuums.”