An auditor reviewing Facebook Inc.’s privacy practices gave the social-media company a clean bill of health in a report to federal authorities last year—well after Facebook discovered that political consulting firm Cambridge Analytica improperly obtained millions of users’ personal data.
“In our opinion, Facebook’s privacy controls were operating with sufficient effectiveness to provide reasonable assurance to protect the privacy of covered information,” the auditing firm, PricewaterhouseCoopers, said in the report to the...