Facebook Chief Executive Officer Mark Zuckerberg shouldn’t stay quiet on the data scandal that has engulfed his company if he wants to save face, according to a public relations expert.

“I think that they really have a mess on their hands – a PR nightmare,” Bob Pickard, principal at Signal Leadership Communication, told BNN in an interview Tuesday. “And they really have to come out and talk about what it is that they’re going to do to deal with the situation at the senior level and to regain the trust of consumers.”

Shares of Facebook (FB.O) fell sharply Monday and extended those losses Tuesday following reports that the U.K. data firm Cambridge Analytica gained access to data on 50 million Facebook users to support Donald Trump’s U.S. presidential election campaign. The reports triggered pushback from privacy regulators in the U.S. and Europe.

Zuckerberg has yet to speak out on the scandal, and Bloomberg is reporting both he and Chief Operating Officer Sheryl Sandberg plan to keep a low profile until the company completes its internal review.

“That vacuum is being filled with critics and naysayers who are questioning the company’s competence and questioning its character under these circumstances,” Pickard said.   

The social network company tried to get ahead of the media firestorm, Bloomberg reported, with a blog post Friday explaining why it was suspending Cambridge Analytica from its site. It also reportedly sent letters to major media outlets ahead of time explaining why the situation didn’t constitute as a breach. But Pickard said Facebook’s preemptive measures aren’t enough.

“It kind of calls into question how sincere is their proactive communication, when they’re basically only saying stuff when they know the press is going to break it anyway on their behalf,” he said.   

“Facebook, whatever they’ve done, it’s being lost now to this cataract of disaster that is coming from all of these different critics,” Pickard added. “They aren’t saying anything. It’s like a failure of leadership communication right now.”

The company shed nearly US$40 billion of its market capitalization Monday and Zuckerberg saw his net worth fall by about US$5 billion.

“There’s clearly a real brand hit,” said SocialFlow CEO Jim Anderson in an interview with BNN Tuesday. “Just look at all the coverage and the level of emotion that people have. I think the real open question is how much staying power there’ll be.”

Pickard said the road ahead for Facebook will have “many different twists and turns.”

“It’s hard to know where this is going to lead them,” he said. “There’s so much happening right now that people just reach a general, simple conclusion: this is a good company, or this is a bad company. I think they’re feeling that it’s the latter.”