When Stephen Scheeler joined Facebook in 2011, the company’s executives thought the social media platform’s role in influencing change was universally good.

“The Arab Spring had just taken place, and all these social causes and movements from gay and lesbian rights to the Ice Bucket Challenge were being propagated by social media,” says Scheeler, who at 47 was the oldest employee at the time he was hired and would go on to become head of the Australian business. “It was a very idealistic and utopian time.”