Facebook CEO Mark Zuckerberg to break silence on Cambridge Analytica data use

Facebook CEO Mark Zuckerberg will speak publicly in the next 24 hours with a "focus on rebuilding trust," a spokesperson for the company told NBC News.

Zuckerberg's statement would be his first since allegations emerged that data on 50 million Facebook users had been taken from the company and used by Cambridge Analytica, a data analysis firm used by the Donald Trump presidential campaign.

Zuckerberg's silence has been notable in the aftermath of the news, which brought new attention to how Facebook had previously allowed connected apps to take data from users that opted in, as well as data from the friends of those users.

Facebook has been under particular pressure to explain why the company did not notify users or the public that its data been used in a way that violated its terms of service. Facebook said on Friday that the company learned of the violation in 2015.

The lack of any public statement or appearance by Zuckerberg or Sheryl Sandberg, the chief operating office of Facebook, had led to growing questions about the company's response to the ongoing crisis. The hashtag "#WheresZuck" began to circulate on Twitter.

Facebook has faced privacy issues before but never with the kind of widespread attention and intensity as had been given to the Cambridge Analytica revelations. Numerous politicians have expressed concern about the story, with Sen. Mark Warner, D-Va., calling for Zuckerberg to testify before Congress. Numerous state attorneys general are launching investigations, and the Federal Trade Commission is reportedly looking into the matter as well.

Facebook stock has dropped sharply in the past two days, wiping out almost $50 billion in value from the company. The stock decline has reduce Zuckerberg's net worth by around $9 billion.