The storm clouds gathering above Facebook are getting darker by the hour.

Less than one day after Facebook suffered an unprecedented outage that lasted for hours and impacted all of the company's media properties (which was blamed on a "server configuration outage"), and just hours after the NYT reported that Facebook is under criminal investigation over its data deals, and that a New York grand jury has subpoenaed records from at least two smartphones manufacturers which gained access to personal data of hundreds of millions of users, moments ago Facebook announced that two top execs had unexpectedly quit the company.

In a blog post to employees published on the company's website, in which he said that he wants "to share some important updates as we organize our company to build out the privacy-focused social platform I discussed in my note last week" adding that "embarking on this new vision represents the start of a new chapter for us", Facebook CEO Mark Zuckerberg wrote that both Chris Cox, Chief Product Officer, and Chris Daniels, CEO of WhatsApp, had decided to leave the company.

For a few years, Chris has been discussing with me his desire to do something else. He is one of the most talented people I know and he has the potential to do anything he wants. But after 2016, we both realized we had too much important work to do to improve our products for society, and he stayed to help us work through these issues and help us chart a course for our family of apps going forward. At this point, we have made real progress on many issues and we have a clear plan for our apps, centered around making private messaging, stories and groups the foundation of the experience, including enabling encryption and interoperability across our services. As we embark on this next major chapter, Chris has decided now is the time to step back from leading these teams. I will really miss Chris, but mostly I am deeply grateful for everything he has done to build this place and serve our community.

Zuckerberg also announced that Will Cathcart will be new head of WhatsApp, and that Fidji Simo will be new head of the Facebook app; meanwhile Zuck said he doesn't plan to immediately appoint anyone to fill Cox's role.

"This is an important change as we begin the next chapter of our work building the privacy-focused social foundation for the future. I’m deeply grateful for everything Chris Cox and Chris Daniels have done here, and I’m looking forward to working with Will and Fidji in their new roles as well as everyone who will be critical to achieving this vision. We have so much important work ahead and I’m excited to continue working to give people the power to build community and bring the world closer together" Zuckerberg wrote.

It was unclear if the departing execs left for a specific reason - i.e., the increasing political scrutiny over the world's most powerful and influential publisher of news - or if they simply wanted to "spend time with their family."

The market is not very excited by this development, and the Stock slumped a further 1.5% after hours, bringing the day's total drop to nearly 4%

Read Zuckerberg's full letter here.