Nicole Perlroth

Now that the U.S. government has cracked open an iPhone that belonged to a gunman in the San Bernardino, California, mass shooting without Apple’s help, the tech company is under pressure to find and fix the flaw.

Apple’s chief executive has moved a once-secretive company into the center of highly charged social and legal issues, as illustrated by his standoff with federal officials over privacy concerns.

A growing body of digital forensic evidence leaves little doubt that an overwhelming percentage of attacks on U.S. corporations and government agencies originate in a Shanghai office tower.