San Francisco, March 21: With Facebook getting mired in its biggest-ever controversy following a massive data breach, everyone is asking one question: Where is its CEO Mark Zuckerberg? Not only Zuckerberg has remained quiet so far, Facebook COO Sheryl Sandberg who has been the face of the company’s PR strategy is yet to speak on the data scandal. According to a report in ReCode on Wednesday, Zuckerberg is slated to address a weekly Q&A session with employees on Friday and he may speak before that meeting. Normally, Zuckerberg or Sandberg come out with long blog posts whenever Facebook gets tangled in controversies but the silence this time is deafening.