When Stephen Scheeler became Facebook's Australia chief in the early 2010s, he was a true believer in the power of the internet, and social media, for public good.
It would herald a new era of global connection and democratise learning. It would let users build their own public squares without the traditional gatekeepers.
"There was that heady optimism phase when I first joined and I think a lot of the world shared that," he told the BBC.
But by the time he left the firm in 2017, seeds of doubt about its work had been planted, and they've since bloomed.
"There's lots of good things about these platforms, but there's just too much bad stuff," he surmises.
