Facebook's director of product management Rob Leathern, who handled the company's advertisement products around sensitive subjects such as politics and coronavirus misinformation, has left the company.

In a series of posts on micro-blogging site Twitter, Rob said: "After almost 4 years, I made the difficult decision to leave Facebook, and 12/30/20 was my last day at FB. I've had a great experience in a difficult, fun, fast-growing and impactful role at the company working with amazing people. I was honoured to call them colleagues!"

"Working on Business/Ads Integrity/Trust at Facebook has been my most rewarding professional experience. While it’s been difficult and demanding work at times, the passionate & dedicated crew I worked with have accomplished a great deal in these last few years!"

"What's next? While I'm not going to be working on ads directly, it will be a part of what I work on as I will be staying in the tech/data/privacy space. I will share more about where I am going in the next week or two."

Rob's team built the enhanced advertiser authenticity and transparency for all ads across Facebook and Instagram, including for ads about social issues, elections and politics.  

His tenure as Director of Product Management had its share of controversies. 

Amid claims of inaction over multiple attacks on the integrity of the U.S. election from President Donald Trump and his supporters, Rob's team in October announced that Facebook will not accept ads that 'delegitimize' US election results.