... Many Saudis had hoped that Twitter would democratize discourse by giving everyday citizens a voice, but Saudi Arabia has instead become an illustration of how authoritarian governments can manipulate social media to silence or drown out critical voices while spreading their own version of reality... Twitter has had difficulty combating the trolls. The company can detect and disable the machine-like behaviors of bot accounts, but it has a harder time picking up on the humans tweeting on behalf of the Saudi government... Twitter executives first became aware of a possible plot to infiltrate user accounts at the end of 2015, when Western intelligence officials told them that the Saudis were grooming an employee, Ali Alzabarah, to spy on the accounts of dissidents and others... Twitter executives... could not find evidence that he had handed over Twitter data to the Saudi government, but they nonetheless fired him in December 2015... After the country announced economic austerity measures in 2015 to offset low oil prices and control a widening budget gap, McKinsey & Company, the consulting firm, measured the public reception of those policies... McKinsey found that... [t]hree people were driving the conversation on Twitter..: the writer Khalid al-Alkami; Mr. Abdulaziz, the young dissident living in Canada; and an anonymous user who went by Ahmad. After the report was issued, Mr. Alkami was arrested, the human rights group ALQST said. Mr. Abdulaziz said that Saudi government officials imprisoned two of his brothers and hacked his cellphone, an account supported by a researcher at Citizen Lab. Ahmad, the anonymous account, was shut down...