Hoping to tamp down the furor that erupted over reports that its user data was improperly acquired by Cambridge Analytica, Facebook has hired the digital forensics firm Stroz Friedberg to perform an audit on the political consulting and marketing firm. In a statement, Facebook said that Cambridge Analytica has agreed to comply and give Stroz Friedberg access to their servers and systems. Facebook has also reached out to the whistleblower, Christopher Wylie, and Aleksandr Kogan, the Cambridge University professor who developed an application that collected data that he then sold to Cambridge Analytica. Kogan has consented to the audit, but Wylie, who has positioned himself as one of the architects for the data collection scheme before becoming a whistleblower, declined, according to Facebook. The move comes after a brutal day for Facebook’s stock on the Nasdaq stock exchange.