The co-founder of messaging service WhatsApp, Jan Koum, announced Monday that he is leaving the platform's parent company Facebook.
The Washington Post reported earlier that Koum is exiting the company after clashing with Facebook over strategy, and that he also plans to leave Facebook's board. The two men, both privacy advocates who started their encrypted messaging app almost a decade ago, joined Facebook after it acquired WhatsApp in 2014 for $22 billion, making them both billionaires.
More recently, according to the report, Koum and other WhatsApp staffers struggled with Facebook's desire to make its new Whatsapp For Business product "easier for businesses to use its tools".
"It's been nearly a decade since Brian and I started WhatsApp, and it's been an incredible journey with some of the best people", Koum wrote on a Facebook post. But it is time for me to move on.
He said people were using WhatsApp in more ways than he could have imagined and the team was stronger than ever.
In post on Facebook, he said he was "taking some time off to do things I enjoy outside of technology". "And I'll still be cheering WhatsApp on - just from the outside".
Facebook Chief Executive Mark Zuckerberg commented on Koum's post, saying he was grateful for what Koum taught him about encryption "and its ability to take power from centralized systems and put it back in people's hands".More news: The World's Oldest Known Spider Dies in Australia
Jan Koum made the announcement on his personal Facebook.
WhatsApp is the largest messaging service in the world with 1.5 billion monthly users.
Zuckerberg is already expected to reiterate some of the apologies he's been offering in the wake of revelations that Facebook allowed Cambridge Analytica, a data mining firm tied to President Donald Trump's 2016 campaign, to obtain personal information from as many as 87 million of its users.
Facebook has been accused of being lax and allowing the transfer of its users' information to companies who then target them with ads, along with revelations of Russian election manipulation in the USA, fake news, data leaks and more.
Facebook scrapped WhatsApp's annual fee but Mr Koum and Mr Zuckerberg ruled out advertising on WhatsApp.
Acton left the messaging service company in September to start a foundation, after spending eight years with WhatsApp.
Messrs. Koum and Acton had clauses in their contracts with Facebook that allowed an acceleration of their contracts if Facebook added advertising to the app. Mr. Koum's contract with Facebook wasn't supposed to end until November, the person familiar with the matter said. Facebook did not address Koum's future role at Facebook when contacted by CNBC. "Those values will always be at the heart of WhatsApp".